Scabies in Sheep and Goats 403 No satisfactory medicinal treatment ment of the thread lungworm larva and for the destruction of thread lung- the intermediate hosts of the hair lung- worms is known. Inhalants and intra- worm and the red lungworm. tracheal injections of various drugs It is desirable to rotate animals to have been tried, but frequently they clean pastures whenever practicable. are more injurious than beneficial to The use of dry feed, in racks designed the host and they are hard to give. to prevent contamination with drop- The hair lungworm can be killed by pings, and uncontaminated water will an intramuscular injection of emetine minimize the acquisition of parasites. hydrochloride, but such a treatment Sick animals and heavily infected should be administered by a veterinar- ones should be kept from contaminat- ian. Emetine hydrochloride is a po- ing pastures with their droppings. They tent drug, and an overdose may result should be removed to dry lots to pre- in serious damage or death. Care must vent additional infection with lung- be used to keep it from contact with worms. the eyes, as it is highly irritant. It An adequate diet, and removal of should not be used near shearing time gastrointestinal parasites by anthel- because it may cause sheep to shed. mintics, remedies for worm infections, Preventing infection is the best are deemed to be of considerable value means of combating lungworms. The in building up the vigor of the animal general measures recommended for and consequently counteracting the ef- keeping livestock healthy apply. fects of lungworm infection. The following measures are espe- cially important in minimizing lung- AARON GOLDBERG is a parasitologist worm infection. The use of wet areas in the Helminth Parasite Section^ Animal for pastures should be avoided as they Disease and Parasite Research Branchy are favorable habitats for the develop- Agricultural Research Center at Beltsville.

Scabies in Sheep and Goats

H. E. KEMPER AND H. O. PETERSON

FIVE KINDS of parasitic mites cause The mites live on blood serum that scabies, or scab, in sheep and goats. oozes from skin punctures, which the Common scabies, or psoroptic sca- mites make with their sharp mouth bies, is highly contagious to all classes parts. Into the tiny wounds they prob- of sheep. It is transmitted readily and ably secrete a poisonous substance. quickly from one animal to another Bluish-red, inflamed, swollen areas by direct contact. surround the puntures. The serum on It is caused by tiny, ovoid, pearl- the skin becomes mixed with debris, white mites, Psoroptes equi var. ovis. which soon dries, hardens, and forms The female mite is about one-fortieth a crust, or scab. As the lesion develops, of an inch long. A hand lens should the skin becomes thickened, hard, and be used when one examines infested wrinkled. It might crack and bleed animals for the mites. The adults have when it is manipulated with the fin- four pairs of brownish legs and sharp, gers. The uniformly thickened condi- pointed, brownish mouth parts. tion of the diseased skin is readily 404 Yearbook of Agriculture 1956 detected by comparing it with the but they may become infested from pHable, healthy skin. premises or bed grounds very recently Chronically diseased areas become occupied by infested sheep. Premises hardened and covered with a tightly that have been vacant for about a adhering, scaly, grayish crust. The month arc safe for use by clean sheep. grayish color results from the accumu- Freshly dipped sheep do not become lation of dried flakes of skin. The wool infested from contaminated premises falls out and leaves bare areas, which and therefore may be safely held there enlarge as the disease advances and between the first and second dippings. make the sheep look naked. The mites It is a good sanitary practice, however, seek the healthier skin at the outer to avoid old bed grounds and unclean edges of a lesion, produce more punc- corrals. tures, and thereby cause the lesions to The disease may be contagious at all spread. The mites can be found most seasons, but new infestations are un- easily at the outer edges of the lesions. common in summer. Scabies often re- The mites cause intense irritation mains dormant during hot, dry weath- and itching. Infested sheep become er and may seem to be cured, but usu- restless and furiously scratch, rub, kick, ally it becomes evident again with the and nibble at their wool. The fleece arrival of cold, rainy weather. soon has a broken, disturbed appear- An attack does not give immunity. ance. From the fleece hang tags or A flock may become infested any num- tufts of wool, which the sheep have ber of times. pulled out with their mouths or Goats and cattle herded with sheep scratched out with their hind feet. may be temporary carriers and may Their discomfort is especially notice- even develop lesions of short duration. able after they have been active. The Therefore they should be included wool on afifected areas within reach of when the flock is treated. the animals' mouths may be dirty and We used to think that psoroptic wet with saliva. Licking the lips and mites of sheep were not transferable to champing the jaws while scratching cattle or to any other class of livestock. are characteristic movements of sheep Tests at the Animal Disease and affected with scabies. Parasite Research Laboratory at Albu- The first lesions usually are on the querque, N. Mex., showed, however, back or sides, but may start on any that common sheep scabies could be part of the body. transmitted from sheep to cattle and The only way to be sure that a sheep then back to clean sheep. Lesions con- has scabies is to find the mites. Any taining psoroptic mites were found on condition that causes the sheep to bite December 27, 1950, on a cow that had and scratch themselves should be in- been kept with 10 scabies-infested vestigated at once. sheep for 15 months. Six months later As the wool is parted over a lesion, the disease appeared on a bull that also the mites move away from the light had been with the sheep. The original and may be picked up on the edge of a infestation on the cow and bull was knife blade. The best way to find mites maintained continuously on them for is to scrape the outer edge of the lesion more than 4 years. Skin scrapings con- with a blunt blade of a pocketknife, taining live psoroptic mites were re- transfer the scrapings to a sheet of moved from the cow every day for 2 black paper, and examine the material weeks and placed in the wool of scabies- under bright light. If the material is free sheep. Live mites became estab- slightly warmed by sunlight or a lamp, lished in the wool 4 days after the first the mites become active. They are transplant. Small lesions and some loss plainly visible with a hand lens. of wool were observed during the first Clean sheep do not commonly con- month. The sheep developed extensive tract scabies from infested premises. and typical scabies within 3 months. Scabies in Sheep and Goats 405

FOOT SCABIES, also called chorioptic shoulders. They also occur over the or symbiotic scabies, is caused by mites back, hips, flanks, ears, and jaws. To known as Chorioptes bovis (of the variety find them, one must run his hands over ovis^ if they are on sheep, or the variety the animal's body. caprae^ if they infest goats). The contents of some nodules can be The mites resemble the common squeezed out between the fingers, but scab mites and live in groups on the sometimes they must be incised. In surface of the skin, usually on the lower order to see the mites, the material parts of the legs and around the feet. from the nodules must be examined They spread to the inner surfaces of under a microscope. They look quite the thighs and to the udder and ab- different from other mites that infest domen in severe cases. livestock. The elongated body is di- Chorioptic scabies is much more vided into the anterior part, which common in goats than in sheep. The bears the head; thorax, with legs at- visible lesions usually occur initially tached; and the abdomen. About lOO around the feet and are most pro- or 125 of them measure an inch. The nounced during cold weather when legs are short and stout. The mites the flock is housed. have sucking mouth parts.

SARGOPTIC SCABIES, often known as PSORERGATIC SCABIES was first found head scab or black muzzle, has been in the United States on sheep in Ohio found on sheep in Europe but not in in 1951. It had been reported on the United States. It is caused by the Merino sheep in Australia in 1941. mite Sarcoptes scahiei var. ovis. The mite causes a mild irritation and The mite burrows into the skin on itchiness like that caused by lice. The the head and face, where there is little sheep bite and scratch the parts most or no wool. Like common scabies, it easily reached, such as the sides, flank, causes intense itching and irritation. and rump. Tags of wool are pulled out, The infested animals rub and scratch and the fleece has a ragged, tangled the affected parts and hard, firmly at- appearance. The tips of the wool fibers tached scabs are formed. arc twisted or curled into locks or Sarcoptic scabies may be told from matted and hang loosely from the sides. common scab by the nature and loca- The psorergatic mites are about one- tion of the lesions and its tendency to third as big as the common scab mite. remain localized on parts that are not The head is short and broad. The gen- covered with wool. eral form of the body is rounded. Eight short legs extend from the sides DEMODECTIC SCABIES usually is re- of the body at equal distances from one ferred to as demodectic or foUicular another. Each leg has a double hook. mange. The mite burrows into the skin, caus- It is quite common in goats. It is ing a slight thickening, roughening, found only rarely in sheep—usually in and scaling of the affected area. The the small glands of the eyelids. The in- scabs are usually loose, dry, and festations in sheep do not cause much crumbly. Moist spots sometimes exist trouble. in the lesion. In goats the mites infest the seba- The small size and burrowing of the ceous, or oil, glands of the skin, which mites make them hard to find. One has become filled with a thick, cheesy sub- to make deep skin scrapings with a stance that contains thousands of scalpel or pocketknife and examine the mites. The swollen glands look like material in light mineral oil under a nodules in the skin. They may be as microscope. The infestation spreads small as a wheat seed or as large as a slowly and may take 3 or 4 years to walnut. The nodules are found oftenest become generalized on a sheep. The at the base of the neck in front of the intensity of infestations may vary year 406 Yearbook of Agriculture 1956 to. year. Some animals appear to re- at least twice for an instant so that cover, but usually there is a recurrence. the wool and hair about the head and face are thoroughly wet. TREATMENT of sheep and goats in- Small lambs should be dipped in a fested with psoroptic and chorioptic barrel. After they are a month old, scabies is with dips approved by the it is safe to let them swim through the Department of Agriculture. The ap- vat, but they should not be put into proved dips contain lime-sulfur, nico- the vat with adult sheep. tine sulfate, wettable BHC, or wettable The dip should be changed as soon lindane. as it becomes filthy, regardless of the Lime-sulfur dips are made in the number of sheep that have been proportion of 8 pounds of unslaked dipped in it. lime and 24 pounds of flowers of sulfur, Because BHC, lindane, lime-sulfur, or sulfur flour, to 100 gallons of water. and nicotine sulfate do not kill or check If commercial hydrated lime, not air bacteria, open cuts or wounds may be- slaked, is used, 11 pounds per 100 come infected with dirty dip. Sheep gallons of water is required. If nicotine that are weak and in poor physical sulfate is used, the dip should contain condition should not be dipped be- not less than 0.05 percent nicotine. cause of the danger (especially when These two dips must be heated and BHC or lindane are used) of killing maintained at 95^ to 105^ F. The them. sheep and goats must be dipped at least twice at intervals of i o to 14 days. No SPECIFIC RECOMMENDATIONS arC Dips prepared from BHC (benzene made for treating sarcoptic, demodec- hexachloride) or lindane should be tic, or psorergatic scabies. prepared from wettable powders and Many treatments have been sug- the content of gamma isomer, the gested for controlling the demodectic active insecticidal ingredient, should mange of goats, but none of them has be maintained at 0.06 percent. BHG been completely eff"ective. The lesions and lindane were approved by the in goats are prominent enough to be Department of Agriculture in 1954 for treated locally. Some of the investiga- the treatment of sheep infested with tors report good results by opening the scabies or exposed to it. They have nodules, removing the contents, and several advantages over lime-sulfur irrigating the pockets with a 2-percent and nicotine sulfate. solution of coal tar-creosote dip. Good Dips prepared from BHG and lin- results also have been had from a few dane must not be heated above 80° F. drops of a saturated solution of carbolic One treatment with BHC or lindane, acid used in a similar manner. properly applied, is enough to cure the In the absence of a satisfactory common form of sheep scabies and foot treatment, the infested animals should scabies of goats. be isolated from the rest of the flock. The dipping vat should be filled Attempts to control psorergatic sca- with enough clean, unheated water bies with BHC have shown some to cover the animals—ordinarily 40 promise, but precise recommendations to 48 inches deep. After the water is depend on further experiments. measured and put into the vat, the One dipping in suspensions contain- required amount of BHC powder is ing 0.06 percent of gamma isomer of added and thoroughly stirred. The wettable BHC or lindane makes it dip should be stirred again after any possible to eradicate psoroptic and interruption in dipping. chorioptic scabies from sheep and Each animal must be held in the dip goats. not less than r minute to assure satura- The use of this simple and reliable tion of the skin and fleece. The head dip and the efliective cooperation of of each animal should be submerged livestock owners and State and Fed- Head Grubs of Sheep 407 eral officials can eradicate this scourge From ig4j to his retirement in ig§§, he of the sheep and goat livestock in- directed research on external parasites of dustry. livestock at the Department's field station at Albuquerque, jSf. Mex. H, E. KEMPER was graduated from the H. O. PETERSON, parasitologist in the Kansas City Veterinary College in 1^14. Agricultural Research Service, joined the He retired from the Department of Agri- Department's field station at Albuquerque culture after more than 40 years of work in in 1946. He has been engaged in research on the field of animal diseases and parasites in the development of treatment of livestock the former Bureau of Animal Industry. affected with ectoparasites.

Head Grubs of Sheep

N. G. COBBETT

HEAD grubs inhabit the nasal pas- remaining motionless in some sheltered sages and adjoining cavities in sheep. spot and so may live for 2 weeks. They cause heavy losses everywhere. The sheep botfly is hard to see—it The grubs are the larval, or maggot, flies fast, and at rest its coloring stage of the sheep botfly, Oestrus ovis, usually blends with the surroundings. which also is called the sheep gadfly But sheep recognize its presence at or nasal fly. The fly is slightly larger once and become nervous and agi- than the common housefly. It is tated. They stop feeding and gather in brownish gray and hairy. It can dart groups with their noses held close to quickly in and out among sheep and the ground. They become alert, stare occasionally hovers in front of a sheep's at the ground, stomp their feet, and nose. Sometimes it remains motionless snort or sneeze. for some time on the ground. Just how the fly accomplishes the The fly has no functional mouth deposition of its young in the sheep's parts; so it does not bite or feed. It has nostrils we do not know. It is thought no stinger. Its sole purpose in life that since practically all sheep become apparently is to reproduce its kind and infested with head grubs, the fly must deposit its young in sheep's nostrils. somehow come in contact with the The female fly deposits tiny larvae— nostrils. Perhaps she does so by quick, not eggs—through a small, flexible darting attacks while hovering in tube, which she extends from the rear front of the sheep's nose or from the of her abdomen. She makes repeated, position she assumes on the ground persistent attacks on different sheep, near the places where sheep are feed- depositing a few larvae at a time. A fly ing or resting. can deposit 500 young grubs during After the sheep botfly makes a her lifetime. When conditions are deposit of her young in or on the favorable she completes her deposition moist edges of the nostrils, the tiny of larvae within a few days and then grubs crawl quickly back into the dies. During periods of cold or stormy nasal passages. There they move about weather, when conditions are not over the mucous membranes, feeding favorable for flight, she conserves her on the mucus secreted by the tissues. energy for later attacks on sheep by Many conceal themselves within the