Livestock-Poisoning Plants of California

Making a Difference for California University of California Agriculture and Natural Resources http://anrcatalog.ucdavis.edu Publication 8398 | November 2010 Livestock-Poisoning Plants of California LARRY FORERO, University of California Cooperative Extension Livestock Advisor, Shasta and Trinity Counties; GLENN NADER, University of California Cooperative Extension Livestock and Natural Resources Advisor, Sutter-Yuba and Butte Counties; ARTHUR CRAIGMILL, University of California Cooperative Extension Environmental Toxicology Specialist, Sierra Foothill Research and Extension Center; JOSEPH M. DITOMASO, University of California Cooperative Extension Weed Specialist, Department of Plant Sciences, UC Davis; BIRGIT PUSCHNER, Professor of Veterinary Toxicology, California Animal Health and Food Safety Laboratory; and JOHN MAAS, University of California Cooperative Extension Veterinarian, School of Veterinary Medicine, UC Davis.

Poisonous plants cause significant losses of livestock With few exceptions, livestock will not eat every year. A successful livestock operator must know poisonous plants unless forced to by hunger. The which poisonous plants occur on a given range or single most important way to prevent poisoning is to pasture and how they can be controlled or avoided. use proper range and pasture management practices This publication shows which plants are poisonous, to provide ample forage, encouraging consumption tells how they affect stock, and suggests ways to of nontoxic plants. Areas infested with poisonous reduce losses from poisoning. plants should be avoided when trailing, holding, or Undesirable effects may result from a single unloading animals. Supplemental feed may protect ingestion of a large amount of a poisonous plant, but stock if these conditions cannot be avoided, but some plants are so toxic that very small amounts may there are circumstances (for example, herbicide result in severe disease or death. Other plants cause applications) that may change palatability or increase chronic poisoning only after ingestion over weeks or toxicity in some plants. If toxic weeds are embedded months. The later situation may result in clinical signs in alfalfa cubes or included in total mixed rations, long after the exposure to the toxic plant material, and animals may not be able to avoid ingestion of them. treatment may no longer be possible. Many poisonous plants may be controlled with herbicides. Often, however, the uneven distribution Livestock-Poisoning Plants of California ANR Publication 8398 2

Diagnosing a plant poisoning can be difficult and Livestock Poisoning by Plants Possible poisonous plant in hay or feed: must be done quickly. In many cases, clinical signs in California What to do are nonspecific (such as diarrhea), and postmortem The California Animal Health and Food Safety • Work with your veterinarian to determine lesions are not characteristic. The assistance of your whether the animals’ clinical sign may be a result (CAHFS) Laboratory System toxicology laboratory veterinarian is crucial. This is especially important of plant exposure. investigated numerous cases of suspected plant in insurance or legal investigations. Producers • Collect the whole plant (if practical) or poisonings from 1990 to 2007. CAHFS veterinary and farm managers, along with veterinarians representative parts of the plant, including toxicologists have diagnosed plants as the cause of leaves, flowers, stems, roots, and fruit, and and diagnosticians, play important roles, and all toxicosis in more than 600 submitted cases, most of have it identified by a trained individual (local contribute information that may be important to these in livestock. The largest number of submissions nursery, county agricultural commissioner, UC diagnose a poisoning case. Once all the information Cooperative Extension Advisor, veterinarian, was for cattle, followed by horses, pigs, goats, and is available, all evidence is collected, and proper diagnostic laboratory, etc.). sheep. sampling of specimens has occurred, a summary • Save suspect plant material or feed for possible The most commonly diagnosed cause of plant of findings will be instrumental in preventing future evaluation. poisoning is ornamental oleander, a nonnative species recurrences. • Once plants are identified, ask your veterinarian (fig. 1). The data from CAFHS are from submitted to contact a veterinary toxicologist for detailed Accurate plant identification is critical if you samples, so they do not necessarily represent the consultation. suspect that a particular plant is causing problems overall occurrence of plant poisonings in California. • If the animal dies, submit it to a veterinary for your livestock. Producers can be most helpful by diagnostic laboratory. providing a grazing history, carefully observing what plants have been grazed, especially suspicious plants. The best approach is to collect the whole plant (if Possible poisonous plant in pasture: What to do practical) or representative parts of the plant, including 1. Work with your veterinarian to determine of poisonous plants on a range or in a pasture makes leaves, flowers, stems, roots, and fruit, and press whether the animal’s clinical sign may be a large-scale chemical control uneconomical. However, them dry in a folded newspaper between two sheets result of plant exposure. small patches of poisonous plants can and should be of cardboard, or roll them up between the pages of a 2. Determine whether a plant is found in your eradicated to prevent them from spreading to other newspaper or magazine. The plant sample can then be area. Visit the Calflora Web site, http://www. areas. The specifics of chemical control of poisonous taken or sent to your local UC Cooperative Extension calflora.org/. plants are beyond the scope of this publication; advisor or county agricultural commissioner office 3. Walk the field, collecting any unusual or toxic plants, and have them identified. see your county Farm Advisor or a UC Cooperative for identification. Local nurseries may also be a good 4. If you cannot identify a suspect plant, take it to Extension Specialist, or contact a pest control adviser source for plant identification. To determine whether your county agricultural commissioner or UC (PCA) for specific recommendations for your area. a particular plant is found in your area, see the Calflora Cooperative Extension office for identification. Web site, http://www.calflora.org/. 5. If an animal dies, submit it to a veterinary diagnostic lab. Livestock-Poisoning Plants of California ANR Publication 8398 3

Although most of the plants discussed in this treatment. Most important, recognition of poisonous publication are not among those that have confirmed plants in hay or forage may help prevent plant diagnoses, it is important to know that they can be poisonings in animals. poisonous. Awareness of poisonous plants growing in The following tables give summary information a certain geographical region, the season when they about livestock-poisoning plants in California. For full are most available, and their associated clinical signs information on plants listed, refer to the descriptions are instrumental in making a diagnosis and initiating in the text.

600 555 Plant PoisoningPlant Poisoning 1990-2007 1990-2007

500

400

300

200 134 Number of Diagnoses Number Diagnoses of 100 78 49 28 22 14 13 10 9 0 Oleander Nitrate Pyrrolizinine Oxalate Oak Avacado Yew Yellow Lupines Foxtails

Accumulators Alkaloid OAK Star YEW Thistle LUPINES OXALATE AVOCADO FOXTAILS FOXTAILS

Figure 1. Sources of OLEANDER plant poisoning in livestock, 1990–2007. Source: CAHFS. THISTLE NITRATE ALKALOID YELLOW STAR YELLOW PYRROLIZIDINE ACCUMULATORS Livestock-Poisoning Plants of California ANR Publication 8398 4

Table 1. Livestock-poisoning plants commonly found in selected regions of California Common name Scientific name Common name Scientific name North Coast starthistle Centaurea spp. arrowgrass Triglochin spp. tree tobacco Nicotiana spp. azalea Rhododendron spp. water hemlock Cicuta douglasii, C. maculata chokecherry Prunus virginiana Sierra Foothills dogbane Apocynum spp. cocklebur Xanthium spinosum, X. strumarium fiddleneck Amsinckia spp. deathcamas Zigadenus spp. milkweed Asclepias spp. dogbane Apocynum spp. ragweed or ragwort Senecio spp. foxtail Hordeum spp. and Setaria spp. rhododendrum Rhododendron spp. klamathweed Hypericum perforatum ryegrass, perennial Lolium spp. larkspur (low) Delphinium spp. tansy ragwort Senecio spp. milkweed Asclepias spp. veratrum (false hellebore) Veratrum californicum oak Quercus spp. water hemlock Cicuta douglasii, C. maculata ragweed or ragwort Senecio spp. South Coast toyon Heteromeles arbutifolia arrowgrass Triglochin spp. tree tobacco Nicotiana spp. chokecherry Prunus virginiana western azalea Rhododendron spp. dogbane Apocynum spp. Sierra Nevada Northern Range fiddleneck Amsinckia spp. chokecherry Prunus virginiana locoweed Astragalus spp. dogbane Apocynum spp. milkweed Asclepias spp. lupine Lupinus spp. tree tobacco Nicotiana spp. Ponderosa pine Pinus ponderosa Sacramento Valley Sierra Nevada Central Range cocklebur Xanthium spinosum, X. strumarium chokecherry Prunus virginiana curly dock Rumex crispus deathcamas Zigadenus spp. dogbane Apocynum spp. dogbane Apocynum spp. fiddleneck Amsinckia spp. larkspur (tall) Delphinium spp. foxtail Hordeum spp. and Setaria spp. Ponderosa pine Pinus ponderosa groundsel Senecio spp. ragwort or ragwort Senecio spp. milkweed Asclepias spp. toyon Heteromeles arbutifolia oak Quercus spp. veratrum (false hellebore) Veratrum californicum oleander Nerium spp. water hemlock Cicuta douglasii, C. maculata ragweed or ragwort Senecio spp. western azalea Rhododendron spp. starthistle Centaurea spp. western bracken fern Pteridium aquilinum tree tobacco Nicotiana spp. East of the Sierra Nevada water hemlock Cicuta douglasii, C. maculata deathcamas Zigadenus spp. San Joaquin Valley greasewood Sarcobatus vermiculatus cocklebur Xanthium spinosum, X. strumarium horsetail and scouring rushes Equisetum spp. curly dock Rumex crispus Ponderosa pine Pinus ponderosa fiddleneck Amsinckia spp. ragweed or ragwort Senecio spp. foxtail Hordeum spp. and Setaria spp. summer pheasant’s eye Adonis aestivalis groundsel Senecio spp. Southern California locoweed Astragalus spp. avocado Persea americana milkweed Asclepias spp. chokecherry Prunus virginiana oak Quercus spp. locoweed Astragalus spp. oleander Nerium spp. ragweed or ragwort Senecio spp. ragweed or ragwort Senecio spp. tree tobacco Nicotiana spp. Livestock-Poisoning Plants ofCalifornia *Nitrate/nitrite: Present in johnsongrass (Sorghum halapense) sudangrass and ( Notes: CAHFS. Source: goosefoot ( goosefoot lambsquarter and goosefoot ( goosefoot and lambsquarter Most commonly diagnosed plant poisonings for selected livestock, in descending order indescending occurrence of livestock, Table for selected plant poisonings 2.Mostcommonly diagnosed ‡ † (Sarcobatus vermiculatus) ; sorrel (Sarcobatus (Oxalis greasewood in Present Oxalate: Pyrrolizidine alkaloids: Present in fiddleneck ( fiddleneck in Present alkaloids: Pyrrolizidine oak pyrrolizidine alkaloids nitrate/nitrite* oxalate oleander Cattle

Chenopodium iStockphoto.com spp.); spp.). (Amaranthus andpigweed Chenopodium perennial ryegrass ryegrass perennial lupine oxalate nitrate/nitrite oleander Sheep spp.). UC ANR ‡ Amsinckia spp.), (Senecio tansy ragwort jacobaea) foxtail dogbane yellow starthistle yellow oleander pyrrolizidine alkaloids Horses spp.); (Rumex dock S.bicolor ); oat hay); oat grass andother and hays; lambsquarters spp.); spp.); (Amaranthus pigweed and † , and groundsel ( groundsel and , oleander lupine oxalate avocado nitrate/nitrite Goats Senecio

H.P. Olmo spp.). AN R Publication 8398 Publication

UC ANR 5 Livestock-Poisoning Plants of California ANR Publication 8398 6

Table 3. Toxic dosage for selected livestock-poisoning plants in California Toxic dosage Plant Cattle Sheep Horses Comments arrowgrass 1.5% bw 5­–2% bw no data Flowering spikes have twice the amount of toxin and require one-half the dosage. The toxic dose range in sheep and goats for fresh leaves, chronic (low dose) and acute (high dose). avocado no data 5.5–20­ g/kg bw no data Cattle and horses are also affected. cocklebur 1% bw 1.5% bw no data Consumption of fresh green sprouts. 0.75% bw no data no data Consumption of germinating plants (lethal). deathcamas 1% bw no data no data Consumption of green plant (lethal). dogbane no data no data no data No conclusive toxic dosage information available. foxtail no data no data no data Mechanical injury. greasewood 2.5 kg/45 kg bw 2.5 kg/45 kg bw no data Toxic if eaten quickly. groundsel and ragwort 5–10% bw‡ no data 3–7% bw Requires a total intake of 25 to 50% bw over several months klamathweed 1% bw* 0.7–0.9 kg no data Toxic concentrations vary by plant phenology and location. locoweed 30–50% bw in dw no data 81 lb† Symptoms appear 2 to 9 weeks after consumption. lupine no data no data no data Depends on lupine species, plant phenology, time of consumption, and species of animal. oak no data no data no data Depends on oak species, plant phenology, time of consumption, and species of animal. oleander 5 leaves 5 leaves 20–30 g leaves Both green and dried leaves are toxic. pine needles 2.2–2.7 kg no data no data Consumption per day for more than 3 days (abortion). poison hemlock 0.2–0.5% bw 0.6­–0.8% bw no data Seed heads are more toxic than other plant parts. tobacco 2% bw no data no data Consumption of this level of fresh plant is lethal. water hemlock 1–12 oz 2 oz 8 oz Consumption of roots. western bracken fern no data no data 3–5% bw Consumption for at least 30 days. yellow starthistle no data no data 600 lb dm Consumption over 1 to 3 months. Not generally considered toxic to cattle and sheep. Milkweed Asclepias species name Estimated toxic dosage for sheep, cattle, and horses common name antelope horns A. asperula >1% bw broadleaf A. latifolia 0.2–0.4% bw Indian A. eriocarpa 0.2% bw narrow-leaved A. fascicularis 0.5–1% bw showy A. speciosa 1–2% bw Source: Adapted from Burrows and Tyrl 2001. Notes: bw = body weight dm = dry matter *500- to 700-pound calves. †Consumed over 4 to 6 weeks. ‡This level consumed in a few days or weeks causes acute liver disease. Livestock-Poisoning Plants of California ANR Publication 8398 7

Table 4. Signs of poisoning and plants commonly responsible CATTLE Organ or Plant Toxin systems affected Signs arrowgrass cyanide blood, all organs sudden death, salivation, heavy breathing chokecherry cyanide cell poison, all organs sudden death, salivation, heavy breathing cocklebur glycosides cell poison, all organs sudden death, weakness, inappetance, incoordination, muscle spasms, convulsions, coma curly dock oxalates, nitrate kidney, blood sudden death, salivation, depression, incoordination, muscle tremors, weakness, coma deathcamas alkaloids nervous sudden death, excessive salivation, lowered temperature, staggering, weakness, coma dogbane/Indian hemp cardiac glycosides heart sudden death, diarrhea, weakness, irregular heartbeat fiddleneck pyrrolizidine liver chronic: appetite loss, weight loss, appetite loss, rectal straining foxtails physical mouth, eyes, skin ulceration and lesions in mouth, tongue, gums, eyes greasewood oxalates kidney sudden death, depression, incoordination, weakness, coma groundsel pyrrolizidine liver chronic: appetite loss, weight loss, rectal straining horsetail thiaminase nervous thiamine deficiency, depression, unsteady gait, incoordination, weakness, seizures, and diarrhea klamathweed hypericin skin photosensitization; sunburn of lips, mouth, and unpigmented skin; blistering, loss of condition larkspur (tall) alkaloids nervous sudden death, tremors, weakness, incoordination, staggering, slobbering, bloat locoweed alkaloids nervous difficulty eating, exaggerated mouth movement, excitability; depression, weakness, weight loss, incoordination lupine alkaloids nervous, reproductive birth defects, abortion, tremors, incoordination, head pressing, seizures gastrointestinal, heart, milkweed cardiac glycosides depression, diarrhea, colic, irregular respiration nervous nightshades alkaloids gastrointestinal gastrointestinal upset, constipation or diarrhea, drowsiness, salivation, weakness oak tannins liver, kidney sudden death, bloody diarrhea, kidney failure oleander cardiac glycosides heart sudden death, depression, salivation, weakness, irregular heartbeat, diarrhea poison hemlock coniine (alkaloids) nervous, reproductive nervousness, trembling, weakness, coma, birth defects Ponderosa pine isocupressic acid reproductive abortion, incoodrination, aimless wander, congenital defects ryegrass alkaloids (ergot) nervous incoordination, staggering summer pheasant’s eye glycosides gastrointestinal gastrointestinal disturbance, diarrhea, decreased gut motility, sudden death tobacco alkaloids (nicotine) nervous, reproductive birth defects, abortion, weakness, staggering toyon cyanide cell poison, all organs sudden death veratrum alkaloids nervous, reproductive birth defects, abortion; labored breathing, salivation, convulsions water hemlock alcohols nervous sudden death, muscle spasms, teeth grinding, severe convulsions bone marrow depression signs; hemmorhage, bloody feces, bloody nasal secretions; western bracken fern glycosides bone marrow, bladder bladder tumors; pink, red, brown urine

Note: The signs listed in this table are commonly seen after the specific plant intoxications. However, other signs may predominate depending on the dosage, duration of exposure, and environmental factors. Diagnosis must be done by a licensed veterinarian and may require toxiciological analysis by a diagnostic laboratory to confirm the plant involved. Primary or usual signs are given in bold. Livestock-Poisoning Plants of California ANR Publication 8398 8

Table 4. Continued SHEEP Organ or Plant Toxin systems affected Signs arrowgrass cyanide blood, all organs sudden death, salivation, heavy breathing chokecherry cyanide cell poison, all organs sudden death, salivation, heavy breathing cocklebur glycosides cell poison, all organs sudden death, weakness, inappetance, incoordination, muscle spasms, convulsions, coma curly dock oxalates, nitrate kidney, blood sudden death, salivation, depression, incoordination, muscle tremors, weakness, coma deathcamas alkaloids nervous sudden death, excessive salivation, lowered temperature, staggering, weakness, coma dogbane/Indian hemp cardiac glycosides heart sudden death, diarrhea, weakness, irregular heartbeat weight loss, appetite loss [sheep are more resistant to poisoning by the pyrrolizidine alkaloids than cattle or fiddleneck pyrrolizidine liver horses, but may be affected by large amounts] foxtails physical mouth, eyes, skin ulceration and lesions in mouth, tongue, gums, eyes greasewood oxalates kidney sudden death, depression, incoordination, weakness, coma groundsel pyrrolizidine liver weight loss, appetite loss horsetail thiaminase nervous thiamine deficiency, depression, unsteady gait, incoordination, weakness, seizures; diarrhea in cattle klamathweed hypericin skin photosensitization, sunburn of lips, mouth and unpigmented skin, blistering, loss of condition larkspur (tall) alkaloids nervous tremors, weakness, incoordination, staggering, slobbering, bloat locoweed alkaloids nervous depression, weakness, weight loss, incoordination lupine alkaloids nervous, reproductive birth defects, abortion, tremors, incoordination, head pressing, seizures gastrointestinal, heart, milkweed cardiac glycosides depression, diarrhea, colic, irregular respiration nervous nightshades alkaloids gastrointestinal gastrointestinal upset, constipation or diarrhea, drowsiness, salivation, weakness oak tannins liver, kidney sudden death, bloody diarrhea, kidney failure oleander cardiac glycosides heart sudden death, depression, salivation, weakness, irregular heartbeat, diarrhea poison hemlock coniine (alkaloids) nervous, reproductive nervousness, trembling, weakness, coma, birth defects Ponderosa pine isocupressic acid reproductive abortion, incoodrination, aimless wander, congenital defects ryegrass alkaloids (ergot) nervous incoordination, staggering starthistle lactones nervous weight loss, abnormal curling of lips (chewing disease), yawning summer pheasant’s glycosides gastrointestinal gastrointestinal disturbance, diarrhea, decreased gut motility, sudden death eye tobacco alkaloids (nicotine) nervous, reproductive birth defects, abortion, weakness, staggering toyon cyanide cell poison, all organs sudden death, salivation, heavy breathing veratrum alkaloids nervous, reproductive birth defects, abortion; labored breathing, salivation, convulsions water hemlock alcohols nervous sudden death, muscle spasms, teeth grinding, severe convulsions

Note: The signs listed in this table are commonly seen after the specific plant intoxications. However, other signs may predominate depending on the dosage, duration of exposure, and environmental factors. Diagnosis must be done by a licensed veterinarian and may require toxiciological analysis by a diagnostic laboratory to confirm the plant involved. Primary or usual signs are given in bold. Livestock-Poisoning Plants of California ANR Publication 8398 9

Table 4. Continued HORSES Organ or Plant Toxin systems affected Signs arrowgrass cyanide blood, all organs sudden death, salivation, heavy breathing avocado persin vascular mastitis (abrupt cessation of milk flow), heart failure chokecherry cyanide cell poison, all organs sudden death, salivation, heavy breathing cocklebur glycosides cell poison, all organs sudden death, weakness, inappetance, incoordination, muscle spasms, convulsions, coma curly dock oxalates, nitrate kidney, blood sudden death, salivation, depression, incoordination, muscle tremors, weakness, coma deathcamas alkaloids nervous sudden death, excessive salivation, lowered temperature, staggering, weakness, coma dogbane/Indian hemp cardiac glycosides heart sudden death, diarrhea, weakness, irregular heartbeat fiddleneck pyrrolizidine liver chronic: appetite loss, weight loss; walkabout disease, head pressing, rectal straining foxtails physical mouth, eyes, skin ulceration and lesions in mouth, tongue, gums, eyes greasewood oxalates kidney sudden death, depression, incoordination, weakness, coma groundsel pyrrolizidine liver chronic: appetite loss, weight loss; walkabout disease, head pressing, rectal straining horsetail thiaminase nervous thiamine deficiency, depression, unsteady gait, incoordination, weakness, seizures locoweed alkaloids nervous depression, stiff gait, incoordination, staring, excitability; difficulty eating, exaggerated mouth movement gastrointestinal, heart, milkweed cardiac glycosides depression, incoordination, trembling, seizures nervous nightshade alkaloids gastrointestinal gastrointestinal upset, constipation or diarrhea, drowsiness, salivation, weakness oleander cardiac glycosides heart sudden death, depression, salivation, weakness, irregular heartbeat, diarrhea poison hemlock coniine (alkaloids) nervous, reproductive sudden death, nervousness, trembling, weakness, coma, birth defects starthistle lactones nervous weight loss, abnormal curling of lips (chewing disease), yawning summer pheasant’s glycosides gastrointestinal gastrointestinal disturbance, diarrhea, decreased gut motility, sudden death eye toyon cyanide cell poison, all organs sudden death water hemlock alcohols nervous sudden death, muscle spasms, teeth grinding, severe convulsions western bracken fern glycosides bone marrow, bladder thiamine deficiency, depression, unsteady gait, incoordination, weakness, seizures

Note: The signs listed in this table are commonly seen after the specific plant intoxications. However, other signs may predominate depending on the dosage, duration of exposure, and environmental factors. Diagnosis must be done by a licensed veterinarian and may require toxiciological analysis by a diagnostic laboratory to confirm the plant involved. Primary or usual signs are given in bold. Livestock-Poisoning Plants of California ANR Publication 8398 10

Table 4. Continued GOATS Organ or Plant Toxin systems affected Signs arrowgrass cyanide blood, all organs sudden death, salivation, heavy breathing

avocado persin vascular mastitis (abrupt cessation of milk flow), heart failure

chokecherry cyanide cell poison, all organs sudden death, salivation, heavy breathing

cocklebur glycosides cell poison, all organs sudden death, weakness, inappetance, incoordination, muscle spasms, convulsions, coma

deathcamas alkaloids nervous sudden death, excessive salivation, lowered temperature, staggering, weakness, coma

fiddleneck pyrrolizidine liver chronic: appetite loss, weight loss

foxtails physical mouth, eyes, skin ulceration and lesions in mouth, tongue, gums, eyes

greasewood oxalates kidney sudden death, depression, incoordination, weakness, coma

groundsel pyrrolizidine liver chronic: appetite loss, weight loss

dogbane/Indian hemp cardiac glycosides heart sudden death, diarrhea, weakness, irregular heartbeat

klamathweed hypericin skin photosensitization, sunburn of lips, mouth and unpigmented skin, blistering, loss of condition

locoweed alkaloids nervous difficulty eating, exaggerated mouth movement, excitability

lupine alkaloids nervous, reproductive birth defects, abortion, tremors, incoordination, head pressing, seizures gastrointestinal, heart, Profound depression and weakness accompanied by staggering; labored respiration, elevated temperatures, milkweed cardiac glycosides nervous dilation of pupils, seizures nightshades alkaloids gastrointestinal gastrointestinal upset, constipation or diarrhea, drowsiness, salivation, weakness

oak tannins liver, kidney sudden death, bloody diarrhea, kidney failure

oleander cardiac glycosides heart sudden death, depression, salivation, weakness, irregular heartbeat, diarrhea

poison hemlock coniine (alkaloids) nervous, reproductive nervousness, trembling, weakness, coma, birth defects

ryegrass alkaloids (ergot) nervous incoordination, staggering

larkspur (tall) alkaloids nervous tremors, weakness, incoordination, staggering, slobbering, bloat

toyon cyanide cell poison, all organs sudden death, salivation, heavy breathing

water hemlock alcohols nervous sudden death, muscle spasms, teeth grinding, severe convulsions

Note: The signs listed in this table are commonly seen after the specific plant intoxications. However, other signs may predominate depending on the dosage, duration of exposure, and environmental factors. Diagnosis must be done by a licensed veterinarian and may require toxiciological analysis by a diagnostic laboratory to confirm the plant involved. Primary or usual signs are given in bold. Livestock-Poisoning Plants ofCalifornia do not feed leavesdo avocado andcuttings not to livestock. toxic ofbirds.report to pet being fruits To avocado possibility the avoid of poisoning, toxicto be to livestock,well-documented particularlyis one There andhorses. goats have been shown leaves Guatemalan some The avocados of varieties. Guatemalan in The of commonvarieties most North are America two avocados the and Mexican Avocado of plants concern. cause intoxications. are Avocado primary the oleander and fenceonby rangelands can the also or feeding tothrowingover animals them of dispose yard Unknowing who poisonings. neighbors trimmings from toxic plants pasture of in or near Planting toxic ornamentals or livestock can cause facilities Plants Ornamental Poisonous normal after resolution of the mastitis. of resolution the after normal thereas areMilk known antidotes. no production usually return not does to failure Treatment doses. heart horses, may at seen higher be symptomatic, is may doses Higher milk-producing result cells. failure. in death from heart In of the destruction to due production of milk cessation abrupt and mastitis leavesvariety)avocado (Reed can result goats by lactating in noninfectious Ingestion of pound of of body per weight about 1ounce fresh Guatemalan treatment and poisoning of Signs (Persea americana)

Avocado (Persea americana) fruit. and leaves Avocado AN R Publication 8398 Publication

Di av d Rosen 11 Livestock-Poisoning Plants ofCalifornia might chew onthat plants paddocks. their growmight chew near resulted leaves are fromto trimmings with hay. access orbaled when Bored horses structurea brown podlike with many small seeds. white or anybe canshade of pink branches. They the or red all summer. is fruit The approximately in diameter, 1to 3inches andgrow in large of clusters ends at the leaves. haveFlowers although long, shorter smallerspecimens areinches showy, thick, andleathery, andgrow opposite each other, are They 8 to 10 often in whorls. ofbecause leaves its resistance are toThe droughtlance-shaped, andinsects. extensively planted is Oleander trimmings. plant is poisoning cause of oleander Themajoris a primary cause shrub common ornamental of animalpoisonings. This Oleander Treatment successful early canas be by started if aveterinarian possible. as mayPoisoning progress rapidly so that animal the may found dead. be irregular Animals mayhave heartbeat. tremors also anddifficulty breathing. avarietyprogresses, of develop animals cardiac the signs, including slow and disease the As salivation, excess depression, andanorexia. diarrhea, include lethal toleaves ahorse can or be acow. Clinical poisoning signs of oleander leaves and flowers The most the are medium-sized 5toxic: to10 dried. is present of plant,andtoxicity plant the parts the in all retained when is They are toxins cardiovascularthe affectprimarily system. oleander The treatment and poisoning of Signs Oleander is not readily eaten, but poisoning of livestock andother horses readily has but not poisoning is eaten, Oleander (Nerium oleander) (Nerium

Oleander (Nerium oleander)Oleander flowers. Oleander (Nerium oleander) pods. Oleander seed AN R Publication 8398 Publication 12 J. M. DiTomaso J.io M. D T maso Livestock-Poisoning Plants of California ANR Publication 8398 13

Other Poisonous Ornamental Plants The book Toxicity of Ornamental Plants to Domestic Animals and Livestock (Philips et al. 1997) contains lists of plants that should not be planted around animals to prevent poisonings. These lists have been combined in tables 5 through 7, below.

Table 5. Deciduous trees that should not be Table 6. Broadleaf evergreen trees or shrubs that Table 7. Vines that should not be planted planted around livestock and horses should not be planted around livestock and horses around livestock and horses Common name Scientific name Common name Scientific name Common name Scientific name black locust Robinia pseudoacacia acacia Acacia spp. clematis Clematis spp.

buckeye, horsechestnut Aesculus spp. andromeda, pieris Pieris spp. common moonseed Menispermum canadense

cherry, plum, peach Prunus spp. boxwood Buxus spp. creeper Parthenocissus spp.

chinaberry, Texas umbrellatree Melia azedarach croton Codiaeum variegatum goldcup, chalice vine Solandra spp.

Chinese chestnut Castanea mollissima daphne Daphne spp. ivy Hedera spp. geranium-leaf aralia, Chinese tallowtree Sapium sebiferum Polyscias guilfoylei lantana, shrub verbena Lantana spp. coffeetree crown of goldtree Cassia excelsa holly Ilex spp. matrimony vine Lycium halimtolium

golden-chaintree Laburnum anagyroides Japanese aucuba Aucuba japonica Mexican flame vine Senecio confusus

golden-raintree Koelreuteria paniculata leucothoe Leucothoe spp. monstera Monstera spp. Japanese pagoda tree, Sophora japonica mountain laurel Kalmia latifolia morningglory Ipomoea spp. Chinese scholartree Kentucky coffeetree Gymnocladus dioicus oleander Nerium oleander philodemdron Philodendron spp. Trachelospermum maple, box elder Acer spp. Peruvian peppertree Schinus molle star jasmine jasminoides spp. osage orange Maclura pomifera photinia Photinia spp. trumpet plant Senecio spp.

Peruvian peppertree Schinus molle pittosporum Pittosporum spp.

walnut Juglans spp. privet Ligustrum spp.

rhododendron, azalea Rhododendron spp.

spurge, euphorbia Euphorbia spp.

St. Johnswort Hypericum spp.

yew Taxus spp. Livestock-Poisoning Plants of California ANR Publication 8398 14

Poisonous Rangeland Plants Livestock suspected of being poisoned by plants on rangeland can create a e challenge in that the plants can be difficult to find in a large expanse of range. This s a b a section discusses the most important rangeland species of concern. t a S D T N A

Arrowgrass (Triglochin spp.) L Arrowgrasses are native grasslike plants. The semicircular fleshy leaves arise from the base of the plant. Leaf clumps are 6 to 8 inches tall. Cattle and sheep are more frequently poisoned by arrowgrass than are horses. In California, arrowgrass is lette, USDA-NRCS P

found in mudflats and alkaline places from the coastal salt flats to springy places l o F

above the timberline. The plants are most toxic when stressed or damaged due to a frost, wilting, stunting, or physical damage (mowing, chopping, etc.). Plants lose Wilm their toxicity with drying. and m a

Signs of poisoning and treatment Willi The toxic compounds in arrowgrass contain cyanide and are found in leaves, fruit, and seeds of mature fruit. The highest concentrations are present in newly developing leaves. Cyanide blocks cellular respiration, and poisoning progresses so rapidly that death usually occurs within minutes after onset. Affected animals may show signs of labored breathing, frothing at the mouth, incoordination, muscle tremors, and convulsions. Specific

antidotes are available from your veterinarian, but they will be effective e s a

Arrowgrass (Triglochin maritima) plant. b

only if treatment is initiated rapidly after the onset of signs. Eradication of a t the plant is not practical. The plant is somewhat palatable to stock, and its a S D T N

occurrence in hayfields should be noted. It should be avoided during dry A L seasons and after frost. SDA-NRCS P , U r e d i e n ch l S A Arrowgrass (Triglochin maritima) inflorescence. Livestock-Poisoning Plants of California ANR Publication 8398 15

Chokecherry (Prunus virginiana) Western chokecherry (P. virginiana var. demissa and melanocarpa), often simply called chokecherry, is a native shrub or small tree 3 to 15 feet tall with flossy, finely toothed leaves. The flowers are white, showy, and fragrant, and they appear in May and June in California. The dark red to black fruit is bitter but edible and grows to ¼ inch in diameter. Chokecherry is found along streams and in damp places in woods and brushy areas. It is found in the coast ranges and the Sierra, generally below 8,200 feet, from San Diego County north. Sheep and goats can be affected, and extensive losses of cattle may occasionally occur. Losses of horses are rare. The younger leaves are more toxic than mature leaves, and by late summer the plant so

may become more palatable and provide good forage for cattle. Wilted leaves are a m o

toxic, and cuttings of the plant should be removed from areas where livestock graze. T i . D M . J Chokecherry (Prunus virginiana) plant. Signs of poisoning and treatment The toxic compounds in chokecherry are the same as those in arrowgrass, so the signs and treatment are identical. In order to prevent chokecherry poisoning, hungry or thirsty animals should not be trailed through areas where chokecherry is abundant. Eradication on a large scale is not practical, but near watering and loafing areas, chokecherry may be removed with a herbicide. so so a a m m o T T i . D . D M M . J J.i o Chokecherry (Prunus virginiana) fruit Chokecherry (Prunus virginiana) flowering stem. Livestock-Poisoning Plants of California ANR Publication 8398 16

Cocklebur (Xanthium spinosum and X. strumarium) Cockleburs are weedy native annual plants that grow to about 3 feet tall. Leaves of common cocklebur (X. strumarium) are roughly triangular or heart shaped and are covered with minute hairs on both sides. The brown or greenish brown fruits, or burs, are covered with stiff, hooked spines and contain two seeds. Cockleburs are found in moist waste places throughout the state, generally at lower elevations. Floodplains, old fields, overgrazed pastures, and stock watering places are common habitats. Spiny cocklebur (X. spinosum) is not as common as common cocklebur and can be distinguished by its smaller leaves and sharp, spiny stem.

Signs of poisoning and treatment

The toxic compound in cocklebur is concentrated in the germinating so a m

plants. The seed and the two-leaf-cotyledon stage of the plant is the most T . D

poisonous. Although the toxin remains potent when these portions of the M J.i o plant are preserved in hay, the toxin is not present in the four-leaf stage Common cocklebur (Xanthium strumarium) foliage. or the mature plant. Cocklebur seeds can also contaminate grains used in concentrate rations fed to livestock. Cases of cocklebur poisoning have been reported in cattle, sheep, and pigs. Consumption of as little as 0.75 percent of body weight of germinating plants can cause death, with signs occurring a few hours after ingestion of cocklebur sprouts or seeds. Signs of cocklebur poisoning in pigs and cattle include depression, weakness, loss of appetite, reluctance to move, incoordination, excitability, muscle spasms, and an unusual gait with erect ears and head held high. Lying down, paddling of limbs, and convulsions followed by coma and death can occur within hours to days of consumption. There is no specific treatment for cocklebur poisoning. Cocklebur should be eliminated with mowing, cultivation, or herbicide use. While cocklebur is highly susceptible to herbicides, more than one treatment is required for complete elimination, because only one so

of the two seeds in a bur germinates in the first year. a m o T i . D M . J Common cocklebur (Xanthium strumarium) flowers on stem. Livestock-Poisoning Plants ofCalifornia turns dry. dark brown when of plantare the All parts toxic. wavy margins; inflorescence flowers and the arethe panicles terminalor racemes with leaves lanceolate areoblong to The and in height. alternate plant that can vary Curly pastures. in irrigated weed acommon is dock It aperennial unbranched is (RumexCurly crispus) Dock the toxin may occasionally affect horses. affect toxin maythe occasionally no effectiveis There treatment. Ruminants most but commonlyare affected, rapidly,within 5hours of Deathfollows consumption. generally within aday. (dullness andlistlessness, andcoma) weakness, incoordination, can occur toxiccompound in curlyThe soluble is poisoning oxalate; signs of dock treatment and poisoning of Signs

Curly crispus) floodplain. (Rumex river dock along AN R Publication 8398 Publication

J.io M. D T maso 17 Livestock-Poisoning Plants of California ANR Publication 8398 18

Deathcamas (Zigadenus spp.) Deathcamas, a member of the lily family, consists of about 6 different species. It is grasslike and has greenish or yellowish white flowers that arise from a burled bulb. Flowers occur in a cluster atop a central stalk. These perennial plants are 4 to 18 inches tall. Deathcamas is found in moist, grassy places below 8,200 feet in both the coastal ranges and the Sierra. Zigadenus paniculatus, commonly known so

as sandcorn or foothill deathcamas, is found in rocky soil in Nevada and Siskiyou a m

Counties and is considered one of the most toxic of the species. The plants begin to T . D M

grow early in the season and are green in the spring. Most losses result from early- J.i o season grazing, when more palatable forage is not available. Toxicity varies with Meadow deathcamas stage of growth: the early stages of growth, especially seeds and fruit, are the most (Zigadenus venenosus) plant. toxic. Sheep are most commonly affected; cattle and horses can be affected but usually find the plant unpalatable.

Signs of poisoning and treatment In sheep, ingestion of 1 percent of body weight of the green plant is lethal, while consumption of 0.2 to 0.5 percent of body weight of the green plant can cause serious illness. Losses of livestock are uncommon but can be very severe when they occur. Range sheep can easily ingest the amount necessary to produce toxicity, especially when hungry. Signs include excessive salivation, depression, colic, trembling, incoordination, drooping ears, respiratory failure, convulsions, coma, and death. Keeping stock off spring ranges that contain deathcamas until ample forage is available is the best way to avoid poisonings. Supplemental feed can be offered to animals to prevent consumption of this relatively unpalatable plant. Herbicides can control large infestations of the plant if applied early in the spring. so a m o T i . D M . J Meadow deathcamas (Zigadenus venenosus) flower head. Livestock-Poisoning Plants ofCalifornia oleander. Dogbane can be found in moist areas throughout the state. areas the moist in throughout found be can oleander. Dogbane hay. in dried in found to those toxicsimilar contains cardiacglycosides plant The elongated are plants cottony bitter Dogbane seeds. andare only consumed when is a long seedpod The (up to 6 inches),narrow, corolla. containing pod cylindrical flowers andwith The thelong. tinged withwhite in fiveare throat scales the of red, and from 2toare ovate, 3inches darkanddowny greenpaler beneath, above, leavesbark.The fibrous branch Stems toward top tall. and are the 20 to 40 inches Apocynum These (Apocynum Indianhemp and Dogbane glycosides, see the oleander section, above. section, oleander the see glycosides, For signs andtreatment with exposure measures to cardiac associated treatment and poisoning of Signs species plants are plants erect, species spreading perennial herbs with tough,

(Apocynum cannabinum) flowering stem. (Apocynum Indianhemp J. M. DiTomaso

spp.) (Apocynum cannabinum) fruit. (Apocynum Indianhemp androsaemifolium) (Apocynum Spreading dogbane plant in flower. in plant

J.io M. D T maso androsaemifolium) (Apocynum Spreading dogbane AN flowers. R Publication 8398 Publication

J. M. DiTomaso 19 J. M. DiTomaso Livestock-Poisoning Plants ofCalifornia ingredients, pyrrolizidine alkaloids, concentrated in the seeds. the in concentrated alkaloids, ingredients, pyrrolizidine be toxic,with can toxic the fiddleneck are andgoats Dried susceptible. less sheep Horses andcattle while are but most pigs are sensitive affected, also to fiddleneck, screenings. hay in wheat in appearing and grain, and alfalfa in weed common a It also generally is counties, 6,000feet elevation. under in sandy places or open foundfour in anumber smallof brown is nutlets.California or black Fiddleneck flowers that arecluster fiddle’scoiled like a found in a Each neck. flower produces stems andleaves andsmall yellow It by hairy characterized coarse, California. is are most commonly responsible cases. for these (PAs).caused by alkaloids pyrrolizidine Two Amsinckia plantgenera, third-most-commonly-diagnosedThe is in California cause poisoning of plant (AmsinckiaFiddleneck practical, grazing with sheep may grazingpractical, appropriate. with be sheep rangeland its On appearancespotty where is concern. not andcontrol is Itsherbicides. appearance, in any amount, in hayis cause for or grain fields to is poor. susceptible is animals an annual herb, As fiddleneck broadleaf failure. liver Clinical objects. signs anddeaththemselves, orare other usually aresult of awkward gait, actively pushing against andbiting fences, ground, the an with along aimlessly, are commonlywandering observed chewing) pressing,(photosensitization). In signs (head neurological horses, membranes), areas mucous sunburn and unpigmented in visible the of discoloration (yellow jaundice loss, weight diarrhea, or constipation firstthe lossdevelop ingestion. animals Affected ofmay dullness, appetite, Clinical in animals. disease signs may appear for not 2to 8months after result can liver chronic, in irreversible poisoning alkaloid Pyrrolizidine treatment and poisoning of Signs Fiddleneck, also called rancher’s fireweed and tarweed, is widespread in is rancher’s called also tarweed, Fiddleneck, and fireweed No proven effective treatment is known, and the prognosis for poisoned Nopoisoned provenfor effective prognosis and the treatmentis known, spp.)

and Senecio and , menziesii var.menziesii menziesii) Menzies fiddleneck (Amsinckia inflorescence. var.menziesii intermedia) Coast fiddleneck (Amsinckia plant.

J. M. DiTomaso Coast var. menziesii fiddleneck (Amsinckia intermedia) plant.

J.io M. D T maso menziesii) var. menziesii (Amsinckia Menzies fiddleneck AN R Publication 8398 Publication flowering flowering stem.

J. M. DiTomaso 20 J. M. DiTomaso Livestock-Poisoning Plants ofCalifornia animals and initiate treatment, initiate necessary. and if animals affected all evaluate to have aveterinarian necessary fed to be livestock not should It animals. may be foxtails with hay contaminated Alfalfa removed. be may and mustbristles be presentwounds The in the in cattle. reported been also has injury mechanical are present. Although mainly aproblem in horses, panicles of foxtail number substantial a and late cut hay the is usually when Problems occur mouth. the erosions causeserious of and membranes mucous penetrate can bristles particularly These yellow foxtail. havepumila) barbedbristles, sharp, species . Both viridis) (Setaria foxtail green largecontained amounts of two different species: ulcerations andlips.alfalfahay tongue The on the mouth blisters andlesionsin the and to develop causedhorses has foxtails with hay contaminated past the fewyears, exposureOver of to horses alfalfa may to abscesses. lead gums, andcheeks tongue, ulcerationspain andreluctance to eat. of Deep the cause andthey areLesions mouth, in the oftenseen aparticularly is bristles serious problem in horses. from areplants the toxic not injury but mechanical The in animals. anddisease with injury associated have been heads orbristles seed spines on their such that foxtails havePlants as barbed sharp, Foxtail (Hordeum spp. (S. (S. foxtail yellow and

Setaria spp.) Setaria and

Foxtail (Hordeum barley jubatum) plant.

J.io M. D T maso AN R Publication 8398 Publication 21 Livestock-Poisoning Plants of California ANR Publication 8398 22

Greasewood (Sarcobatus vermiculatus) Greasewood is a shrub 2 to 6 feet tall with densely interlocking stiff, spiny, white- barked branches. Leaves are ½ to 2 inches long, bright green, strap-shaped, and somewhat fleshy. The greenish flowers are small and inconspicuous and give rise to cone-shaped fruiting spikes about ½ inch long. In the fall, after the leaves have so

dropped, the spines are more conspicuous. In the California deserts, greasewood a m

may retain its leaves as an evergreen. T . D

In California, greasewood is found in alkaline places in desert valleys between M J.i o 3,000 and 7,000 feet from Mexico north to Lassen and Modoc Counties. Sheep are most commonly poisoned, but cattle may be poisoned as well. The highest concentrations of the toxin (soluble oxalates) are in the leaves. If large quantities are Greasewood (Sarcobatus vermiculatus) plant. ingested, the rumen’s ability to detoxify oxalates is overwhelmed, and the oxalates may cause kidney damage. Early spring seems to be the most common season for poisonings. If consumed with other food, greasewood is valuable forage. Problems arise when greasewood is the major component of an animal’s diet.

Signs of poisoning and treatment Signs of poisoning (dullness and listlessness, incoordination, weakness, and coma) can occur within 5 hours of consumption. Death follows rapidly, generally within a day. There is no effective treatment. Since greasewood is a dominant plant in much rangeland east of the Sierra and provides useful forage, control is not practical. Provision of supplemental feed when greasewood is the only available forage will reduce losses. so a m o T i . D M . J Greasewood (Sarcobatus vermiculatus) stem. Livestock-Poisoning Plants ofCalifornia longer overlap. Three and do not of Senecio species commonly have(rays)petals yellow flowers the that though daisies, resemble are sunflowershrubs in the family. They in California. occur fortyAbout species ( and ragworts groundsels The (Senecio Ragwort and Groundsel are more resistant toxic to the effects. of Seneciocases to be an effectiveto be control biological tansy for ragwort. treatmentsmoth have jacobaeae)The cinnabar (Tyria effect. no proved has later are plants the most rapidly; applied growing if herbicide when or horse feeding. Senecio with more than Senecio 5percent ofcontent hay remains many constant over contaminated months. Silage alkaloid pyrrolizidine The discarded. be should feed contaminated and control best prevention measure. the is Feed carefully, inspected be should by andcattle. horses prolonged to the delay in onset of Due clinical signs, no effectiveis There treatment. Heavily infested beavoided should ranges for fiddleneck. described are those as same Clinical the signs andrecovery treatment and poisoning of Signs Plants are usually not palatable and are poisonous both fresh and dried. Most are freshPlants both usually and are anddried. palatable not poisonous • • • coastal ranges, the Sierra Nevada, and the White Mountains White andthe ranges,coastal Sierra the Nevada, areas northern the in integerrimus) wooded in found , (S. groundsel western counties coast North jacobaea) (S. tansy ragwort waste places and hayfields, of vulgaris) weed gardens,, acommon alfalfa (S. groundsel common species poisoning are andcattle, in horses seen poisoning andgoats species sheep as species can be controlled with an appropriate controlled can be species Senecio spp.) are alarge groupand of wildflowers

, found creekin , found pastures and bottomlands in the species is considered unsafe is for cattle species spp.) are of concern: special (Senecio vulgaris) plant. (Senecio groundsel Common Tansy (Senecio ragwort jacobaea) infestation.

J. M. DiTomaso jacobaea) Tansy (Senecio ragwort plant. AN R flowering flowering stem. vulgaris) (Senecio groundsel Common

J. M. DiTomaso 8398 Publication

J. M. DiTomaso 23 J.io M. D T maso Livestock-Poisoning Plants of California ANR Publication 8398 24 l Horsetail and Scouring Rush (Equisetum spp.) a Horsetails and scouring rushes have dark green, hollow, jointed or segmented Ne J. stems ¼ to ½ inch thick with no true leaves. Stems may be singular or have whorls of branches in horsetails. Scouring rushes lack the whorl of branches. Jointed shoots emerge from the underground rhizome system and have conelike structures when mature. They can be found in riparian pastures and also in meadow hays.

Signs of poisoning and treatment Horsetails and scouring rushes contain an enzyme (thiaminase) that destroys thiamine, a vitamin necessary for normal brain function. All parts of the plant, both fresh and dried, are toxic. Horses are most severely affected, and occasionally cattle and sheep. Newborn calves that are sucking cows consuming horsetails or scouring rushes are most susceptible. The calves will show signs of lying down and convulsions with the head arched straight Field horsetail (Equisetum arvense) infertile stem and branches. back. Remove animals from the infested field or feed. Treatment includes the administration of thiamine. l a Ne J. so

a Field horsetail (Equisetum m so o

a arvense) fertile stem. T i m . D o T i M . J . D so M a . J m o T i . D M . J Scouringrush (Equisetum hyemale ssp. affine) stem. so a m

Giant horsetail o T

i Smooth scouringrush (Equisetum telmateia ssp. . D (Equisetum laevigatum) stems. M

braunii) stems. . J Giant horsetail (Equisetum telmateia ssp. braunii) along creek in native habitat. Livestock-Poisoning Plants ofCalifornia sheep are susceptible. sheep especially but any animallight-skinned affected, may adverselybe Newlyshorn affected. forage other unavailable. Young is when cattle are andsheep most commonly onlyis eaten and is unpalatable northwardClara Counties plant The into Oregon. from Tuolumne CountyandSanta fromCruz CoastRange Santa andin the north Klamathweed in pastures 4,500 grows Sierra in under feet the fields andabandoned pinhole-like that dots and have are against small, translucentlight. held the when top ofthe stems. Leavesare the arranged stems along the opposite each other orange, flowers the marginsblackdots five-petalled along have and at borne are dark, The aweedyyellow-Klamathweed perennial is that up to grows 2½feet tall. (Hypericum perforatum) Johnswort Klamathweed St. or is effective in controlling larger infestations. controlling in effective is biological control by klamathweed of the while klamathweed, patches beetle application Proper of may aherbicide weed. controlcontrol localized the dark-coloredAllowing to graze animals infested ranges may helpful to be sunlight. Animals severely not are affected likely uneventfully.to recover unthrifty. and weak kept from become be animals should animals Sensitized or turn seekshade away will rareanimals Deathis from sun. the but affected to severe andpainfulmild to reduced andcan lead feed intake. Affected be can skin and damage swelling on darkly areas. Local occur pigmented skin to sunlight, on anunpigmented animal exposed that not andit is does is extent damage skinof that severe.typicallythe The can be limited to the skin in the andinteractaccumulate with sunlight to produce asunburn substances photoactive or phototoxic when occurs Photosensitization toxin a results that photosensitization. in contains Klamathweed treatment and poisoning of Signs

Klamathweed, or common St. Johnswort or(Hypericum common perforatum)Klamathweed, flowers. St. Johnswort or(Hypericum common perforatum)Klamathweed, plant. AN R Publication 8398 Publication

J. M. DiTomaso

J.io M. D T maso 25 Livestock-Poisoning Plants ofCalifornia and palatable earlyand palatable remain plants spring. in the Dried toxic. have matured. larkspursLow seedpods areuntil period the flowering the highly toxic sufficientand contains toxinspoisoning. to cause larkspurs Tall most are toxic from “toxicwindow,” during the occur palatable larkspuris plant aspecific when time the Most stage andthe of growth. species on the concentrations poisonings depend larkspurof in California All buttoxin species are the consideredaffected. poisonous, significant losses of cattle. are but are and Horses, goats sheep susceptible rarely cause can and state ranges the throughout foothill and mountain in communities areas. of grow number a in Larkspurs plant desert and are grassy in found hillsides ravines. andshaded larkspurs Low aremountain meadows, thanand less 3feet tall Tall larkspurs grow andare like 3to 7feet tall stream foundplaces in moist sides, to pink or lavender) with flowers a trumpet-shaped prominent end. spur at one spikes or leaves divided andslender (sometimes or of blue lobed purple white Larkspurs are by characterized palmately (spreading like fingers the hand) of a (Delphinium Larkspur biological control. biological consideredbe can for to effectively avoided Sheep be poisoning. prevent conditions. Exposure of cattle must to larkspurs “toxic window” during the appropriate range on canlocal be measures,with herbicides depending andspraying patches, localized hand-grubbing more widespread stands useful Fencing only is made. animals is arapid if areas, affected diagnosis Treatment of are larkspur stands extensive causeforconcern. of affected forage other present, is cattle Because when animals. eat larkspur even will falling,and sudden bloat, andrespiratory distress. stress not Do poisoned staggering include exposure.4 hours after they If clinical signs are observed, fatal amount thatto the cattle. is to 5times Cattle are 3to oftenfound dead and paralysis. Cattle can about tolerate 4 sheep are while most susceptible, function (especially diaphragm in the andesophagus), muscle weakness, toxinslarkspursThe in have a curare-likeaction that result in loss motor of treatment and poisoning of Signs spp.) flowering and fruiting fruiting stem. and flowering Tall larkspur glaucum) (Delphinium Tall larkspur glaucum) (Delphinium plant.

J. M. DiTomaso

J. M. DiTomaso J.io M. D T maso nudicaule) Red larkspur (Delphinium AN R Publication 8398 Publication flowering flowering stem. 26 Livestock-Poisoning Plants of California ANR Publication 8398 27

Locoweed and Milkvetch ( spp. and ssp.) so Astragalus Oxytropis a m o T

More than 90 species of locoweeds are found in California. They are generally low or i . D

small bushy plants with white, purple, yellow, or orange pealike flowers. Leaflets are M . J arranged opposite each other along the stem, with a single leaf extending from the tip of the stem. The seedpods are often inflated, giving rise to the name rattleweed. Locoweed is found in a number of plant communities and on a variety of soils but usually on dry and open sites. All parts of the plant are toxic at all stages of growth and when dry.

Signs of poisoning and treatment Locoweeds (loco is Spanish for “crazy”) can cause a number of diseases, but it is important to note that some locoweeds are nontoxic and can be used as forage. Locoweed poisoning, or locoism, can lead to abnormal behavior, infertility, abortion, heart failure, weight loss, and poor performance. Locoism has been reported in horses, cattle, sheep, goats, and elk. In horses, clinical signs of locoism include depression, circling, incoordination, and a staggering gait. Affected horses are difficult to handle and unpredictable and thus unsafe to ride. Cattle Shorttooth Canadian milkvetch (Astragalus consuming locoweed at high altitude can develop congestive right-sided heart canadensis) plant. failure, also known as “high mountain disease.” Clinical signs of poisoning are

usually seen after consumption of large amounts of locoweed for 2 to 9 weeks; however, poisoning so a

can occur almost immediately after ingestion. Livestock like to eat locoweed when it is in the flower m T

and in the early seedpod stages, when the plant is most palatable and also contains the highest . D M concentration of toxins. Signs of poisoning may last for several weeks, and the occasional animal that J.i o Locoweed (Astragalus recovers is generally unthrifty and will eat locoweed to the exclusion of other forage if returned to a oxyphysus) plant. locoweed-infested pasture. Young animals seem more affected. Fetuses are especially susceptible to the effects of locoweed at 30 to 60 days gestation. Chronic poisoning can lead to “cracker heels,” in which cattle and sheep click their hooves together while walking, knuckle over at the fetlocks, show r ele

posterior paralysis, are unable to stand, and have difficulty breathing (“roaring disease”). There is no e h

specific treatment for the treatment of locoism and cracker heels, and animals usually do not recover. . W . C L Locoweeds also accumulate potentially toxic selenium concentrations. Ingestion of plants with Locoweed (Astragalus high selenium concentrations can cause chronic selenosis in cattle and horses. trichopodus and Astragalus oxyphysus) flowers and fruit. Livestock-Poisoning Plants ofCalifornia site, http://www.calflora.org/. ofmajor diet. To the part any of lupinesare Calflora the whether these see area, found in your determine Web lupinesconstitutehighly may valuable toxic, a supplemental when andsome provide forage. occur Problems by lupine areplants in set. hay. seed Animals dangerous after may especially poisoned be Not lupinesare all livestock.all toxic The occur and areplant substancesthroughout in the concentratedthe lupine seeds; in the may plants but toxic the be to commonly poisoned, andcattle goats, are sites.Sheep, sandy most or dry areas mountain and on commonly foothill in found are They are they on. growing improve soil the however,legumes, nitrogen lupinesfix and generally arethey usually found on poorer sites.Like other ofwere nutrients soil to thought rob the since once plants these ,” and word for Latin “wolf , the lupus from “lupine” comes name The to 6feetfrom tall. 6inches characteristic Lupines may ofseedpod legumes. vary pealike into a develop spike. on ashowy borne They more are commonly and purple, blue pealike andare yellow, Flowers, maypalmate. white, which be pink, or family. group pea and varied in the Leavesare lupines(table8)are the alarge locoweeds, Like the Lupine (Lupinus abnormalities. No effectiveis known. treatmentanimals poisoned of on ranges lupineset. causescongenital Adjustment where breeding in the may schedule necessary be avoiding trailing lupine areas (especially animals when sheep) seeds the andby after plants avoiding the lossesmostforageplants, frequently other scarce. by Poisoning reduced lupine is can be when by occur in calves that from ingestedlupine between cows day 40and70of pregnancy. with most poisonous As heavily, anddie.Crooked congenital comatose, orabnormalities legs other may seen be convulse, become mayanimals aimlessly, wander push against andappear dizzy. objects, collapse, finally breathing They muscular include trembling, of Affected lupineSigns poisoning acute andexcitement. incoordination, treatment and poisoning of Signs spp.)

J. M. DiTomaso Yellow bush lupine arboreus) (Lupinus plant. flowering flowering stem. arboreus)(Lupinus Yellow bush lupine

J.io M. D T maso J. M. DiTomaso (Lupinus bicolor) (Lupinus lupine plant. Annual that can be toxicthat be can Table spp.) California of 8.Lupines (Lupinus woolly-leaved or velvetwoolly-leaved plumas or woodland spur tailcup or silvery sicklekeel seashore eddymountain meadow rustylow or bush longleaf grassland orwestern dwarf broad-leaved Anderson’s Common name Scientific name L. leucophyllus L. onustus L. arbustus L. argenteus L. albicaulis L. littoralis L. lapidicola L. polyphyllus L. pusillus L. longifolius L. formosus L. lepidus L. latifolius L. andersonii AN R Publication 8398 Publication flowering flowering stem. bicolor)(Lupinus lupine Annual 28 J. M. DiTomaso Livestock-Poisoning Plants ofCalifornia concentrated in infested watering areas, holding pens, orovergrazed pastures. pens, areas, holding infested watering in concentrated are animals hungry are when Plants andmost lossesoccur unpalatable, in sheep. in hay.greatest Most but the have losses occurred affected, can livestock be species their and toxicity isbe found hayfields, in can retained below7,000feet. They places Milkweeds seeds. are dry in found hairy and seedpod, clusters, boat-shaped a grow three from These have and 1 tall to 4 feet species umbrella-shaped flower well. many milkweeds because types other of usedto identify have be plants cannot it as narrow,long, essentially hairless leaves. All three have milky species sap, sap but the orspiralwhorled milkweed Mexican (A.fascicularis) arrangement. whorled has are they in a milkweed, in woolly-pod attached of on stem; opposite sides the leaves attached directlyhairy leaves In are milkweed, showy main tostem. the eriocarpa) milkweed andshowy (Asclepias (A.speciosa) mostly have both broad, to plants livestock. Woollypod are poisonous as species important milkweed At of but Only leastmilkweeds are 3 14species in California, known to occur (Asclepias Milkweed appear 2 to 14 hours after the plant is eaten. Narrow-leaved eaten. plant is the appear 2to 14 hours after quietlycome without spasms or convulsions. usually Signs with aloweredand stands Death may andhumped back. head alowered has depressed body temperature, anddull, becomes bloat, andexcessive mouth, animal salivation The are noted. primarily cause gastrointestinal distress. Foul odors from the milkweeds woollypod broad-leaved The and showy down. irregular respiration,weakness, cardiac arrhythmias, lying and to respiratorydue failure. Cardiac signsdepression, include death and convulsions, weakness, incoordination, discomfort, or abdominal colic include conditions. of Signs poisoning andgrowing but toxin with species ones, concentrations vary broad-leaved milkweeds are toxic less than narrow-leaved Milkweed toxins. In toxins are general, tooleander similar treatment and poisoning of Signs spp.)

windblown seed and also by rootstocks. and also seed windblown are difficult control to they spread since widely by scattered early may necessary. be in fall, in spring Milkweeds andlate especially feeding, Supplemental range proper and management. hays contaminated avoiding measures include Preventive days. may a lethalandanimals dose, consumed in several recover Supportive therapy that for animals have recommended not is no is Therespecific treatmentmilkweed for poisoning. dead. found maybe but animals also eaten, plant is the 14 hours after of Signs usually narrow milkweed appear poisoning extended. may downandshow fall are legs spasms the in which rigidly with narrow-leaved milkweed poisoned In animals addition, broad-leaved milkweeds, namely depression andweakness. with seen is signs similar tomilkweed what some produces

(Asclepias speciosa) milkweed (Asclepias Showy J. M. DiTomaso plant. (Asclepias fascicularis) stem. (Asclepias milkweedMexican whorled AN R Publication 8398 Publication 29 J.io M. D T maso Livestock-Poisoning Plants ofCalifornia have white flowers, while those those of while silverleaf flowers,have are violet. nightshade white or blue to brownish (silverleaf S. nightshade, S. (cutleaf nightshade, be when ripe may green that isafruit berry small tomatolike The flowers.eight yellow(penduncles) centralflowers in The groups small borne to are parts. one of and bright petals with or flower tomatolike, the lobes star-shaped is five species poisonous three characteristic of mostthe important identifying general The tuberosumSolanum cultivated, andthe closely tomato is related nightshades. to the is cultivated The potato inAt California. ofoccur leastnightshades 20species ( Nightshade preferably summer. setin seeds before the by hand-grubbing, accomplished best is plants within 1to 2days. Control of or recovery the are by they death followed andcoma; lying down, drowsiness, progressive or weakness paralysis, system signs include or without Nervous blood). (with diarrhea or constipation, vomiting, pain, abdominal salivation, of loss appetite, include Signs intoxicated. become to of nightshades large amounts must consume Animals fatal. rarely is quite erratic, is andpoisoning species hazard spring.in the The variousof nightshade autumn the in than higher often is toxin content more toxicoverall thanplant The stems or roots. areBerries more toxic are than leaves, which areUnripe more berries toxic berries. than ripe anddegree of plantmaturity. ingested, plant part conditions, environmental to due widely vary toxicityThe can of agiven nightshade species treatment and poisoning of Signs Solanum

triflorum spp.) ), dull black (black nightshade, S. nightshade, (black ), dull black

elaeagnifolium ). Cutleaf and black nightshades nightshades black and Cutleaf ). carolinense) plant. Horsenettle (Solanum

nigrum) , or yellow yellow or , carolinense) Horsenettle (Solanum

J. M. DiTomaso rostratum) flowering stem. (Solanum Buffalobur leaves.

J. M. DiTomaso J. M. DiTomaso

nigrum) nightshade Black elaeagnifolium) (Solanum nightshade Silverleaf J.io M. D T maso plant with fruit (inset). plant. (Solanum (Solanum elaeagnifolium) (Solanum nightshade Silverleaf AN R Publication 8398 Publication flowering flowering stem.

J. M. DiTomaso C.m El ore 30 J. M. DiTomaso Livestock-Poisoning Plants of California ANR Publication 8398 31

Oaks (Quercus spp.) California is home to many oak tree species that are present in the valley and in coastal and mountain ranges. They produce acorns at levels that can vary from year to year. The highest level of acorn production may occur under drought conditions. All parts of the oak vegetation contain tannins and phenols of various concentrations. Poisoning is usually associated with the consumption of large amounts of buds, leaves, and acorns for 2 to 3 days or longer. Most cases of oak poisoning have been reported in cattle, but horses have also experienced digestive disturbances after eating them. Sheep, and to a lesser degree goats, can also be affected. Goats have tannin-binding proteins in their saliva and a slower digestive system that allow them to tolerate twice as much tannin as can cattle. Deer have even more effective tannin-binding salivary proteins that allow for a high intake of tannins without any adverse effects. Young oak buds emerging in the spring contain the highest concentrations of tannins. This was demonstrated by the late- spring snowstorm of 1985 that limited feed options, when cattle consumed newly s

emerging oak leaves and buds, killing an estimated 2,700 calves from 60 ranches in e on

three northern California counties. . K J Coast live oak (Quercus agrifolia).

Signs of poisoning and treatment Tannins can irritate the digestive system and produce bloody scours (diarrhea). Continued consumption can also lead to kidney damage. In small calves, oak exposure can be lethal, while larger cows may never recover from the poisoning, remaining thin due to impaired kidney function. Sick animals can be supported by providing fluid therapy for hydration and antibiotics to prevent secondary bacterial infections. If cows consume a diet made up largely of acorns, buds, or leaves during the third to seventh month of gestation, congenitally malformed “acorn calves” may be born. These calves have very short legs, abnormal hooves, and short noses or long narrow heads. Oak poisoning may be prevented by providing adequate feed, s especially during droughts; if a late-spring snowstorm occurs, range cattle e on J .

should be fed hay immediately. K Coast live oak (Quercus agrifolia) acorns. Livestock-Poisoning Plants of California ANR Publication 8398 32

Poison Hemlock (Conium maculatum) Poison hemlock is often confused with water hemlock because of their similar names and general appearances. Poison hemlock is distinguished by the purple spots on the lower stems of the plant and by different leaves. Both plants have hollow stems and small white flowers arranged in an umbrella-like cluster. The leaves of poison hemlock look somewhat like parsley or wild carrot and give off a disagreeable mousy order. The plants grow 3 to 6 feet tall. Poison hemlock is poisonous to all classes of livestock and to humans as well. Livestock seem to eat it most frequently in the early part of the growing season. It is found in low waste places on dry or moist (but not saturated) fertile ground, generally below 5,000 feet. Poison hemlock loses its toxicity when dried, but caution is warranted when large amounts are found in hay. Ensiling does not reduce the toxicity of poison hemlock.

Signs of poisoning and treatment Signs of poisoning develop 1 or 2 hours after exposure and include

nervousness, trembling, and weakness (especially of the hind limbs). so a Animals have a weak pulse and irregular heart rate, lie down, and may m T

become comatose prior to death. Poison hemlock can also cause birth . D M J.i o defects in cattle, goats, and pigs, similar that caued by lupines. Prognosis Poison hemlock (Conium maculatum) plant. is poor in affected animals. The plant may be killed by herbicides if treated before it begins to bud. so a m o T i . D M . J Poison hemlock (Conium maculatum) stem with purple blotches. Livestock-Poisoning Plants of California ANR Publication 8398 33

Ponderosa Pine (Pinus ponderosa) Consumption of Ponderosa pine needles can cause late-term (last trimester) abortions in cattle. The abortions are caused when cows eat green pine needles from trees, windfalls, or from the ground. Lodgepole pine (P. contorta) and common juniper (Juniperus communis) can contain the same toxin and can also cause abortions.

Signs of poisoning and treatment The needles contain a toxin that restricts the blood flow to the placenta, leading to abortion in 2 to 21 days after exposure. The greatest risk is in the last 3 months of pregnancy. Reported intakes to cause abortion are 5 to 6 pounds of pine needles per day for more than 3 days; abortion rates can range from 0 to 100 percent. Before the abortion occurs, a bloody mucous discharge from the vulva may be observed. Cows usually retain the placenta after aborting and may not have sufficient milk production. Weak calves should be checked to make sure that they receive enough milk. Cows may require treatment for the retained placenta. Management strategies to reduce the chance for abortion or weak calves include removing cows from pastures that have ponderosa pine trees during the last trimester of pregnancy, fencing areas that have ponderosa pine, and cutting down trees. Making sure that cows have enough roughage or feed during snow or rain storm significantly decreases the risk of poisoning. ura m a k a G. N Ponderosa pine (Pinus ponderosa) Livestock-Poisoning Plants of California ANR Publication 8398 34

Ryegrass (Lolium spp.) and Dallisgrass (Paspalum dilatatum) Ryegrass “staggers” can affect sheep, cattle, and sometimes horses. In California, it is diagnosed most frequently in sheep. Both ryegrass and dallisgrass staggers are caused by a toxin produced by fungal growth on seed heads rather than the plants themselves. Ryegrass is well adapted to the North Coast climate of California, where it is a common component of pastures. In certain locations, however, there is a recurrent problem with ryegrass staggers in the late summer when an endophytic fungus (Neotyphodium lolii) produces tremorgenic mycotoxins (lolitrems). Similar signs occur with dallisgrass in the Central Valley on irrigated pastures or in the fall when continuous rain occurs while seed heads are present and become infected by the ergot-like fungus Claviceps paspali. Rather than flat-looking seeds on the heads, infected heads have gray to black swellings that have a sticky sap material on them. so a m T

Signs of poisoning and treatment . D M J.i o Affected animals show neurological signs including trembling and Perennial ryegrass (Lolium perenne) plant. incoordination and may sometimes show aggressive behavior. Signs of ryegrass staggers are greatly aggravated when animals are stressed. Poisoned animals that are stressed or excited will start running but then develop tremors and fall down. In severe poisonings, animals go down and remain down for several days. Convulsions and death can occur in extreme cases. Affected ewes may have drastically reduced milk production after lambing. Remove animals from infested pasture and provide clean feed. In mild cases of staggers, animals are best left undisturbed or shifted quietly without a dog to a safer paddock with trough water instead of being left in a field with open water that they might fall into and drown. Drifting animals through an open gate rather than driving might be necessary in more severe cases. Some operators leave gates open in the pasture and feed hay in another area to allow the animals to move from the pasture on their own. so

Animals that are severely affected and unable to stand must be provided a m o T

with adequate feed and water. i . D M . J Dallisgrass (Paspalum dilatatum) plant. Livestock-Poisoning Plants of California ANR Publication 8398 35

Starthistle (Centaurea spp.) Yellow starthistle (Centaurea solstitialis) and purple starthistle (C. calcitrapa) are members of the large and diverse sunflower family. An annual weed, starthistle is branched from the base and grows to 2½ feet tall. The flowers grow out of a spiny enclosure. The leaves and stems are densely covered with fine hairs. Yellow starthistle is widely distributed in California, with poisonings reported in the Central Valley and coastal and Sierra foothill areas below 5,000 feet. It is often a weed of hayfields, where it is a cause for concern. Horses, donkeys, and mules are the only animals poisoned by the plant. Affected animals may acquire a taste for the plant and eat it even when it is mature and thorny. The plant is poisonous throughout the year, but two peaks in poisoning have been observed in California, from June to July, and from October to November. A horse must consume more than 600 pounds of the plant over a period of 30 to 45 days before poisoning develops.

Signs of poisoning and treatment so

Signs of Centaurea species poisoning are distinctive in horses and have been a m

termed “chewing disease.” An affected horse will show continuous chewing T . D

movements, frothing of saliva, difficulty eating, frequent yawning, and an M J.i o open mouth with a protruding tongue. When attempting to drink, affected Yellow starthistle (Centaurea solstitialis) plant. horses submerge their heads deeply into water buckets and then tip their heads back. Abnormal curling of the lips or tongue may also be seen. Once horses show these clinical signs, they do not recover from the disease and will die. It is important to recognize the specific signs and the characteristic spiny flower heads in hay or pasture. The weed may be controlled by the

application of an appropriate herbicide, if practical given the size of the k r infestation. No effective treatment for poisoned animals is known. An a . Cl K . infested pasture may be safely grazed by classes of livestock other than J Yellow starthistle (Centaurea horses, if forage is sufficient. solstitialis) flowering head. Livestock-Poisoning Plants ofCalifornia unpalatable, which is most likely is are which ofunpalatable, why reports rare. poisoning flowershaveand the waxy, pheasant’sSummer orangepetals. consideredis eye The stems of pheasant’ssummer leaveseye have are the ridges, linear feathery, foundacontaminant in as alfalfa andgrass been andhas California hay. counties naturalized Northern United in some Itestablished western in the well States. is into North America ahorticultural as cultivation plantbut escaped now andis pheasant’sSummer buttercup aplantin the eye is family that introduced was Summer Pheasant’s Eye (Adonis aestivalis) are to summer much pheasant’s susceptible less eye than are horses. animals that these cattle in indicated studiesfeeding conducted sheep and or decreased gut motility. diarrhea, enteritis, hemorrhagic Acute andchronic pheasant’s gastrointestinal eye develop disturbances such colic, as of toxins. In addition to cardiac toxicity, with summer poisoned horses ofto those oleander.concentrations Leavesandflowershave highest the toxinsThe in pheasant’ssummer areeye and poisoning signs the of similar treatment and poisoning of Signs

Summer pheasant’sSummer aestivalis) (Adonis eye fruit. and flower AN R Publication 8398 Publication 36 J.io M. D T maso Livestock-Poisoning Plants ofCalifornia if other forage available. other not if is arebut they generally andare unpalatable only eaten of classes to all livestock andto humans,poisonous are county Plants of California. in almost every occurs often on sandy ANicotiana or rocky soil. are plains, or flood of plants places waste tobaccos with awaxy, like acabbage Wild leaf. bloom, whitish bluish green are leaves, which nonhairy oftencovered 20 feet, yellow flowers and trumpet-shaped), (also twoother by its shrubby, habit growth of taller 5to Tree from (N. these glauca) distinguished tobacco is cream flowers. trumpet-shaped or greenish white usually strongly hairy, scented, andsticky shrubs with obtusifolia N. N.trigonophylla, Two (desert tobacco, species in California. occur Three toxicof tobacco species Tobacco (Nicotiana forage way best the to prevent is poisoning. are provision ofspecies unpalatable, ample and pigs.Nicotiana goats, Because sheep, cattle, in hemlock caused by poison and lupine tothose similar defects birth produce can Tobacco usually rapid. is Death constipation. by followed often is which diarrhea, and may showanimals excessive also salivation Affected death. and breathing,heavy coma, twitching, staggering,paralysis, convulsions, shaking, include and poisoning hemlock poison similar to are very of poisoning Signs acute treatment and poisoning of Signs , and coyote tobacco, N. attenuata) are tobacco, , andcoyote spp.)

species species

Coyote tobacco (Nicotiana attenuata) plant.

Tree (Nicotiana glauca) tobacco flowering stem. J. M. DiTomaso

J.io M. D T maso attenuata) flowering stem. Coyote tobacco (Nicotiana Tree (Nicotiana glauca) tobacco plant.

J. M. DiTomaso AN R Publication 8398 Publication 37 J. M. DiTomaso Livestock-Poisoning Plants of California ANR Publication 8398 38

Toyon (Heteromeles arbutifolia) Toyon is also known as tollon, Christmas holly, or Christmas berry. The plant is a native evergreen shrub or tree with bright red fruit in the winter. Although it is native to California and Baja California, toyon is also widely planted as an ornamental. Its natural habitat includes chaparral, oak and conifer woodlands, and mixed-evergreen forests up to 3,300 feet elevation. The plant is also used as a Christmas decoration.

Signs of poisoning and treatment The toxic compounds in toyon are the same as those in arrowgrass, thus the signs and treatment are identical. Toyon poisoning has killed goats that were offered fresh clippings. In order to prevent toyon poisoning, animals should not be offered toyon clippings or have so a

access to toyon in their environment. m T . D M J.i o Toyon (Heteromeles arbutifolia) plant. so a m o T i . D M . J Toyon (Heteromeles arbutifolia) flowering stem. Livestock-Poisoning Plants ofCalifornia forage is scarce. forage is cattle eat commonly it andgoats only plant,while eat the will other if leaves. Sheep are roots the more stages at of all toxic growth; thanstem or the poisonous plant is The California. of mountains Southern higher andthe CoastRanges, northern to 11,000feetSierra, in the swampsfrom in moist grows sea level andmeadows plantan appearancestalk, givingthe similar to atasseling plant.Veratrum corn July in appear orAugust branched in clusters atop areunbranched an and borne cream-colored leaves. The boat-shaped parallel-veined greenish or yellow flowers Veratrum, by characterized large is plantof acommon mountain meadows, wet (Veratrum californicum) Veratrum, Lily Corn or False Hellebore, making animals much atmaking animals less risk. firstthe trimester of pregnancy. Frost toxicity the reduces plant, of the convulsions. during especially to It limit to important veratrum, access is pressure, low blood heartbeat, labored breathing, salivation, and vomiting, slowed include analarge animal2 to eaten 3hours after has signs will dose rarely ingest large amounts ofsigns, neurologic enough veratrum to develop animals on days 28to 32,in limb While defects. death and, in embryonic pregnant to veratrum on days sheep 19through 21of gestation may result of have gestation cyclops (“monkey-face,” will eye). with asingle Exposure of to pregnant born that Lambs ingestsusceptible. ewes veratrum on day 14 but cattle,commonly are in sheep, andhorses seen llamas, also goats, toxinsdefects affect arebrain. Birth causethe andalso birthmost defects early July, concentrations highest the contain roots in August. while The concentrations highest The leaves toxin in occur of fromthe to June treatment and poisoning of Signs

Veratrum (Veratrum californicum) plants.

J. M. DiTomaso meadow. a in Veratrum (Veratrum californicum) AN R Publication 8398 Publication 39 J.io M. D T maso Livestock-Poisoning Plants ofCalifornia considered toxic. considered mature stems are minimally leaves anddry toxic. However, of plantare the parts all an animal Newly root. eats the spring emerging in the plants are most toxic, while when occur of most cases poisoning tops are Plant of seldom eaten; California. Waterhemlock. grow marshy in wet, andalong streams hemlocks places in most havecompared distinct withmore leaflets the branching,leaves poison dissected of Water by leaves, which their hemlock from may distinguished poison be hemlocks concentration highest tuberous characteristic the andcontains is of root toxin. ofThechambered, thatseries base partitionsatmay the ayellow contain fluid. have hollow, a They clusters andgrow to 9feetfreely tall. branchingwith a stem of carrot members the family,other flowers in umbrella-shaped small white bear of classes to all livestockare to humans. Water andalso poisonous like hemlocks, Water They in North plants America. are most poisonous the among hemlocks Water (Cicuta douglasii Hemlock maculata) C. and palatable to livestock. to palatable must kept from be treated the area sprayed, are because plants more wilted animals measures If control are chemical used, dead. when poisonous remain rootstalks the because dugup andburned, be should Plants from critical areas have to is animals prevent toaccess poisonings. which onset andrapid acute the progression. removal Diligent of hemlock water for cattle, for Treatment horses. and8ounces rarely is of because possible 1 to 12 ounces exposure.lethal fordose sheep, The of freshis 2 ounces roots Death usually 1to 3hours after movements. occurs chewing and vigorous convulsiveand include salivation, incoordination, seizures, lying down, suddenly, occur ofSigns poisoning usually within anof half hour ingestion, treatment and poisoning of Signs

(Cicuta maculata) plant. Spotted waterhemlock Spotted waterhemlock (Cicuta maculata) flowering stems.

J.io M. D T maso AN R Publication 8398 Publication 40 J. M. DiTomaso Livestock-Poisoning Plants of California ANR Publication 8398 41

Western Azalea (Rhododendron occidentale) Both landscape and native Rhododendron species have woody, evergreen or deciduous shrubs. The simple leaves alternate on either side of the stem, and are smooth or toothed margined. Flowers are borne in a terminal cluster and are tubular, 5-parted, and white to deep pink or yellow. The fruit is in an elongated capsule.

Signs of poisoning and treatment Signs of poisoning include salivation, decreased heart rate, nausea, weakness, difficulty breathing, progressive paralysis, and coma. Vomiting may also be seen in goats. so a m T . D M J.i o Western azalea (Rhododendron occidentale) plant. Livestock-Poisoning Plants ofCalifornia frequently poisoned, but sheep and pigs can also be affected. be andpigs can also but sheep frequently poisoned, (underground rhizome root the stem) most toxic. being Cattle are andhorses most greenin are logged plants Both areas, anddried toxic, andalong roadsides. with along pasture edges, commonlyCalifornia woodlands andis foundopen in moist, Western undergroundwoody system. root bracken in distributed widely fern is harbor brown the spore-bearing organs. from creeping, a arise black, fronds The leaflets edges under, The of arethe rolled and in matureedges therolled-up fronds compound). divisions (leaves)(bipinnately several with fronds triangular broad widespread western bracken aquilinum)The by characterized fern (Pteridium is (Pteridium Fern Western aquilinum) Bracken forage value can also help reduce losses due to poisoning bybracken western reduceforage help to poisoning lossesdue fern. can also value usually takes 3years. for feeding Supplemental decreased endof at the grazing the to compensate season by eradication cultivating for 2to tops 3years Complete the early soil or the mowing season. in the or 20percent morecontaining may of plant brackenwherebe eradicated The western feasible fed. fern is hay when most is seen horses often in Poisoning is causeconcern. bracken for western fern in hayfields of Occurrence forage other depleted. is bracken when fall western in the most commonly fern is observed blindness,” forcattle “bright and described been Intoxication retinal irreversible an degeneration. from in cattle bladder has syndrome ansimilar acute to what primarily can develop 3to 4years of age. Sheep mortality. andhigh in urine, blood in feces, Additionally, bracken western fern may cause tumors in the blood andvagina, of syndrome by from mouth, an characterized acute bleeding nose, development the and nursing In animals. cattle, bracken western fern exposure for more than 1to 2months to can lead excretedis and thus compound in presentsmilk marrow for depression. This arisk tohumans bone lead can that compound bracken toxin western a cancer-causing is in Another toxin. fern by affected this are seriously they not so rumen, administration the in the thiamine produce can Ruminants of thiamine. muscle tremors, Treatment seizures, uncoordinated gait, andlying constipation, down. colic, includes system loss, depression, blindness,depression, feed weight refusal, central include days. Signs nervous that in horses bracken haveoccur 3towestern adiet5percent containing consumed fern for at least 30 breakdown can (thiamine), ofB1 vitamin deficiency.deficiency tothiamine leading Severe thiamine Western bracken fern avariety contains of toxins, principally that thiaminase, ancausesthe enzyme treatment and poisoning of Signs

aquilinum) frond. Western brackenfern (Pteridium developing frond. developing aquilinum)(Pteridium Western bracken fern AN R Publication 8398 Publication

J. M. DiTomaso 42 J.io M. D T maso Livestock-Poisoning Plants ofCalifornia likely to occur if the nitrate level exceeds 1 percent (10,000 ppm). 1percent likely nitrate exceeds the if to occur level (3,000ppm)percent are poisoning andabove dangerous, with acute potentially generallyor seeds toxic Forage contain do not nitrate levels. of nitrate 0.3 levels andgrain concentrations highest material andstems.the Leaf lower stalks in the nitrate In in plants. nitrate vegetative in the addition, tissue,creating accumulates cloudy weather, temperature decreased increased and concentrations of yield Conditions such of heavyfertilization as pastures, application, drought, herbicide nitrateconcentrations. toxic potentially contain also can alfalfa and toxicosis, hay, oat plants, with nitrate andsorghum associated have been corn, especially have found nitrate to contain been toxic at potentially concentrations. Among crop ( orgoosefoots lambsquarter toxic concentrations of spp.), (Amaranthus nitrate. pigweeds Among weeds, the accumulate can crop pasture of and number A common weeds and plants Nitrate Accumulators additional of risk in animals. nitrate the approachesto minimize poisoning high-carbohydrate hay andtesting and forage feed, for nitrate are content with appropriatesupplementating conditions, under harvesting fertilizers, a large reduction of nitrate within 1to 2months. Careful of use nitrogen nitrate alterthe not concentration of ensiling plants, of forages results in does drying While and forage.contents, rumen fluid, ocular blood, serum, analysis on of laboratory based nitrate is andnitrite in Diagnosis ingestion. rapid andconvulsions. Deathmay within heartbeat, 6to 24hours of occur havedepressed, difficulty develop breathing, and tremors,incoordination, color. adark become makes brown blood animals the or chocolate Poisoned sometimes which of methemoglobin, formation Nitrate the causes blood. areruminants caused by a reduction capacity oxygen-carrying in the of the of in nitrate toSigns nitrate acute susceptible poisoning poisoning. (e.g., pseudoruminants and Ruminants alpacas) and are llamas very treatment and poisoning of Signs Chenopodium

Solanum spp.) spp.), (Solanum andnightshades Common lambsquarters (Chenopodium lambsquarters album)Common plant. Tumble albus) (Amaranthus plant. pigweed

J.r K. Cla k AN R Publication 8398 Publication 43 J. M. DiTomaso Livestock-Poisoning Plants of California ANR Publication 8398 44

References For Further Information Burrows, G. E., and R. J. Tyrl. 2001. Toxic plants of North America. Ames: Iowa State To order or obtain ANR publications and other products, visit the ANR Communication Services online catalog at http://anrcatalog.ucdavis.edu or phone 1-800-994-8849. You can also place orders by mail or FAX, or request University Press. a printed catalog of our products from Phillips, R. L., J. Karlik, and M. Fowler. 1997. Toxicity of ornamental plants to domestic University of California animals and livestock. Oakland: University of California Division of Agriculture and Agriculture and Natural Resources Natural Resources Publication 21564. Communication Services 1301 S. 46th Street Building 478 - MC 3580 U.S. Customary–Metric Conversions Richmond, CA 94804-4600 Telephone 1-800-994-8849 Conversion Factor Conversion Factor 510-665-2195 U.S. Customary for U.S. Customary for Metric to Metric FAX 510-665-3427 to Metric U.S. Customary E-mail: [email protected] inch (in) 2.54 0.394 centimeter (cm) ©2010 The Regents of the University of California foot (ft) 0.3048 3.28 meter (m) Agriculture and Natural Resources acre (ac) 0.4047 2.47 hectare (ha) All rights reserved. fluid ounce (fl oz) 29.57 0.034 milliliter (ml) No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the written permission of ounce (oz) 28.35 0.035 gram (g) the publisher and the authors. pound (lb) 0.454 2.205 kilogram (kg) ounce per pound (oz/lb) 62.5 0.016 gram per kilogram (g/kg) Publication 8398 ISBN-13: 978-1-60107-674-8 Fahrenheit (ºF) ºC = (ºF – 32) ÷ 1.8 ºF = (ºC x 1.8) + 32 Celsius (ºC) The University of California prohibits discrimination or harassment of any person on the basis of race, color, national origin, religion, sex, gender identity, pregnancy (including childbirth, and medical conditions related to pregnancy or childbirth), physical or mental disability, medical condition (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or service in the uniformed services (as defined by the Uniformed Services Employment and Reemployment Rights Act of 1994: service in the uniformed services includes membership, application for membership, performance of service, application for service, or obligation for service in the uniformed services) in any of its programs or activities. University policy also prohibits reprisal or retaliation against any person in any of its programs or activities for making a complaint of discrimination or sexual harassment or for using or participating in the investigation or resolution process of any such complaint. University policy is intended to be consistent with the provisions of applicable State and Federal laws. Inquiries regarding the University’s nondiscrimination policies may be directed to the Affirmative Action/Equal Opportunity Director, University of California, Agriculture and Natural Resources, 1111 Franklin Street, 6th Floor, Oakland, CA 94607, (510) 987-0096. For information about ordering this publication, telephone 1-800- 994-8849. For assistance in downloading this publication, telephone 530-754-3927. An electronic copy of this publication can be found at the ANR Communication Services catalog Web site, http://anrcatalog.ucdavis.edu.

This publication has been anonymously peer reviewed for technical accuracy by University of California scientists and other qualified professionals. This review process was managed by the ANR Associate Editor for Animal, Avian, and Aquaculture Sciences. web-11/10-SB/RW