DIVISION OF AGRICULTURE RESEARCH & EXTENSION UJA--University of Arkansas System Agriculture and atural Resources
FSA3073 Livestock Health eries Blackleg and Other Clostridial Diseases
symptoms. Therefore, prevention of Heidi Ward, Introduction these diseases through immunization
VM, Ph Clostridial bacteria cause several is more successful than trying to treat
Assistant Professor diseases that affect cattle and other infected animals. and Veterinarian farm animals. This group of bacteria is known to produce toxins with varying effects based on the way they enter the Blackleg Jeremy Powell, body. The bacteria are frequently Blackleg, or clostridial myositis,
VM, Ph found in the environment (primarily in affects cattle worldwide and is caused Professor the soil) and tend to multiply in warm by Clostridium chauvoei. Susceptible
weather following heavy rain. The animals first ingest endospores. The bacteria are also found in the intes - endospores then cross over the gastro - tinal tracts of healthy farm animals, intestinal tract and enter the blood-
where they only cause disease under stream where they are deposited in
certain circumstances. The most muscle tissue in the animal’s body.
common diseases caused by clostridial They then lie dormant in the tissue bacteria in beef cattle are blackleg, until they become activated and enterotoxemia, malignant edema, black trigger the disease.
disease and tetanus. These diseases Clostridium chauvoei is activated
are usually seen in young cattle (less in an anaerobic (oxygen deficient)
than 2 years of age) and are widely environment such as damaged,
distributed throughout Arkansas. devitalized or bruised tissue. Events
Bacteria of the Clostridium genus such as transport, rough handling or produce long-lived structures called aggressive pasture activity can lead to endospores. Endospores are forms of muscle damage that compromises bacteria that are extremely resistant to blood flow, resulting in decreased environmental conditions (heat, oxygen delivery to that area. In these drought, UV radiation and chemical areas of damage, the clostridial endo- disinfectants). When endospores are spores germinate and multiply into the introduced into an animal, they can disease-causing bacteria. Open wounds develop into the infectious bacteria. are not necessary for this disease to Once the bacteria begin to grow, they develop, making diagnosis difficult. cause disease by producing and Although blackleg has occurred releasing toxins into the animal’s body. in calves as young as 2 months of age, Clostridial diseases are typically the disease generally affects animals Arkansas Is infectious but not contagious. In other between 6 months and 2 years of Our Ca pus words, cattle that become infected will age as they are rapidly growing. not directly transmit the disease to Occasion ally, infections may be seen other cattle. Animals afflicted with in immuno compromised adult cattle. clostridial diseases usually die very In Arkansas, blackleg infections typi- Visit our web site at: s .uada cally occur during the late summer http ://www.uaex .edu quickly, sometimes without any prior
University of Arkansas, United States epartment of Agriculture, and County Governments Cooperating and early fall, when weather is warm and wet. susceptible to tetanus than other domestic livestock Incidence of disease increases after floods due to such as horses; however, they are still at risk. Clos - endospores rising to the surface of the soil or during tridium tetani is introduced into the animal’s body drought when grass is very low, which allows cattle to through injury such as deep puncture wounds, ingest spores more readily when grazing. castration, banding and dehorning. Animals infected with blackleg usually die The incubation period for tetanus is approximately rapidly without any signs of illness. If clinical signs 10 to 21 days. Clostridium tetani produces a very are seen very early in the progression of disease, potent toxin that affects the nervous system. Clinical they will include lameness, loss of appetite, high fever signs that develop include flared nostrils, prolapsed and depression. Animals quickly die within 12 to third eyelid, stiff tail, extended “sawhorse” stance and 48 hours after contracting the disease. Although treat- difficulty chewing food (hence the name “lock jaw”). ment usually fails, appropriate doses of penicillin may Affected animals will exhibit severe muscle tremors prove helpful. If an animal does survive, it will suffer and will experience violent spasms when stimulated by from a permanent defect in the tissue where the touch or sudden sounds. infection occurred. A veterinarian can treat tetanus with antibiotics, Swelling of affected muscle tissue (leg, neck, hip, tetanus antitoxin and supportive therapy if detected chest, shoulder or elsewhere) is the most common early in the disease process. Additional medication to clinical sign of blackleg seen in dead animals. The control seizures may be needed. Intravenous fluids are swelling is due to fluid and gas accumulation produced indicated to control dehydration if the animal cannot eat by the anaerobic bacteria in the muscle tissue. When or drink. Prevention can be achieved through vaccina- pressure is applied to the affected areas, gas can often tion and diligence in using clean surgical instruments be felt moving while producing a crackling sound when castrating or dehorning. under the skin. Affected muscle tissue will contain dark areas of necrotic tissue that gives off a foul odor Malignant Edema often described as rancid butter. Malignant edema is caused by the bacteria Clostridium septicum. This clostridial bacteria is found Immunization is an inexpensive and effective way to in the intestinal tracts of most domestic livestock where prevent blackleg. Calves should be vaccinated between it is shed in feces that in turn contaminate the pasture. 2 and 3 months of age. Until that age, calves should be Malignant edema develops when the bacteria enters the protected through passive transfer of antibodies from body through an open wound. Once in the body, the their dam’s colostrum. A regular vaccination protocol bacteria invade the subcutaneous tissue, causing should be followed at weaning. Calves should receive localized fluid accumulation (edema). Symptoms may vaccine dosages according to the manufacturer’s label. include decreased appetite, high fever and localized Some vaccines require one injection followed by a swelling near the injured area. Lesions in the dead booster in 2 to 6 weeks. Other vaccines are now animal include darkened discoloration of the affected approved for a single dose injection. The common tissue and a foul odor, but the tissue swelling will not blackleg vaccines are called “7-way” because they also have gas accumulation. Death occurs quickly after infec- protect against other clostridial diseases. In accordance tion, so treatment with an antibiotic is only effective if with Beef Quality Assurance standards, vaccines should started very early in the disease. Malignant edema is always be given subcutaneously (under the skin) in the neck area. also best controlled through immunization of cattle. If an outbreak of this disease occurs, the producer Red Water should contact his her local veterinarian to initiate an Red water disease is caused by the bacteria action plan. The veterinarian may recommend that all Clostridium haemolyticum. These bacteria gain entry animals receive immediate vaccination and followup into the animal’s body by crossing the intestinal lining boosters. Further losses may occur for a 2-week period after ingestion of spores. These spores eventually lodge until the animals develop immunity against the disease. in the liver where they lie dormant until the conditions
Carcass disposal should be done carefully by burying are right for them to replicate and grow. Damage to carcasses deeply where they lie as movement of the the liver by liver flukes (Fasciola hepatica) is often the carcass can further contaminate the pasture with trigger for the spores to become active, which is why clostridial endospores. this disease is limited geographically. Aquatic snails are needed for flukes to complete their life cycle, so Tetanus cattle must be in areas with considerable standing Tetanus is a disease caused by Clostridium water. If no liver damage occurs, the conditions will tetani, a bacterium found worldwide in soil and in not be right for growth of the bacteria. the intestinal tracts of many animals. Cattle are less Once infection begins, Clostridium haemolyticum weakness, abdominal distention, bloody diarrhea, releases a toxin into the blood that attacks and uneasiness (straining or kicking at abdomen) and destroys red blood cells. The resulting damage leads convulsions. Postmortem lesions normally seen are to a reddish discoloration of the urine, hence the bloody, fluid-filled small intestines that give rise to the name “red water disease.” Early treatment is essential common name “purple gut.” if the animal is to survive. Otherwise, some animals Calves with this disease need immediate treatment may be found dead before clinical signs are noticed. with intravenous fluid therapy with electrolytes to Symptoms include red urine, dehydration, fever, labored breathing, pale to yellow mucous membranes correct dehydration and acid-base imbalance. Antitoxins and anemia. Prevention of this disease is through and a broad-spectrum antibiotic are usually given in immunization and control of fluke infections through addition to fluid therapy. Despite treatment, calves can an appropriate parasiticide. Not all clostridial vaccines die from this disease. Prevention is achieved through immunize against this disease, so check the label if consistent control of the calf’s diet and herd vaccination. you need to purchase a vaccine that contains the Cows should be vaccinated initially at 60 and 30 days
Clostridium haemolyticum bacterin. before calving and then once annually.
Overeating Disease Black Disease Black disease (infectious necrotic hepatitis) is Overeating disease is caused by Clostridium caused by Clostridium novyi type B. Black disease is perfringens type D. These bacteria are also normally similar to red water disease in that the bacteria prefer found in the gastrointestinal tract. Unlike type C to colonize the liver, where liver damage initiates (above) which affects younger calves, type D affects
activation of the spores. The differences are that a diet older calves less than two years of age that are on a high in grain seems to be the culprit for liver damage high grain ration, such as feedlot or stocker calves. instead of flukes and that the toxin released causes Although overeating disease can occur in cattle, it is further liver damage instead of damage to red blood more common in sheep. Ingestion of excessive amounts cells. Although flukes are not thought to be a primary of feed or grain can hasten the disease. Clinical signs cause, a fluke infestation may create a desirable may include decreased appetite, weakness, incoordina- environment for this disease to occur. tion, diarrhea and nervous signs. Death may occur very quickly even before signs of illness occur. Treatment On postmortem examination, the liver will have and prevention are the same as with type C. large areas of damaged tissue that are gray to black in color. The dark color is what gives rise to the name “black disease.” The diseased areas will also be associ- Botulism Botulism is caused by Clostridium botulinum and ated with a foul smell. Infected animals often do not occurs very rarely in cattle in the United States. The show clinical signs and die before treatment can be disease tends to be associated with the ingestion of considered. Vaccination is the best method for feed contaminated with preformed botulinum toxin, preventing black disease. which is a neurotoxin. The use of poultry litter in cattle feed has been linked to sporadic outbreaks of Enterotoxemia botulism in cattle. Clinical signs include ascending
Enterotoxemia is an often fatal disease in young paralysis that starts in the hind legs and progresses calves caused by Clostridium perfringens type C. It is up the spinal cord, usually leading to death. Since this usually seen in newly born calves less than 30 days old. disease is so rare, there are no protective vaccines
Although Clostridium perfringens type C is a normal available. No specific postmortem signs are associated inhabitant of the gastrointestinal tract, these bacteria with the disease, and treatment is ineffective because can cause severe disease under certain circumstances. death occurs very quickly. The clinical signs associated with enterotoxemia are due to the release of endotoxins. There are six types of toxins released by C. perfringens, of which types B, C Summary and D seem to be the most important in cattle. This Clostridial bacteria can be found in the disease has a sudden onset, and some calves will die environment as resistant spores or in the gastro- without showing any symptoms. intestinal tracts of animals as a normal inhabitant. Diseases caused by these bacteria are very difficult to The sudden increase in the calf’s dietary intake treat because the toxins act quickly. Immunization seems to the most important contributing factor in the through vaccination is the best way to prevent the formation of the disease. When calves overconsume horrible diseases associated with these organisms. milk, they disturb the delicate balance of bacteria in Many of these vaccines are marketed in a combined the gut, which allows for clostridial bacteria to grow manner (7-way), which allows the producer to protect unchecked and secrete toxin. Clinical signs include against several diseases with one vaccine. The vaccine label should always be read carefully as vaccines can differ drastically from manufacturer to manufacturer. References Radostits, Otto, Clive Gay, Kenneth Hinchcliff and Following the label exactly will allow for proper use Peter Constable. “Diseases Associated with of the product which will decrease the chance of Clostridium Species.” Veterinary Medicine: A vaccine failure. Injections should always be adminis- Textbook of the iseases of Cattle, Horses, Sheep, tered subcutaneously in the neck area of the animal Pigs and Goats. 10th ed. Edinburgh and New to avoid damaging expensive carcass cuts. Producers York: Saunders Elsevier, 2007. pp. 821-846. Print. should work closely with a veterinarian to develop an overall herd plan and to quickly address any Aiello, Susan, Michael Moses and Dana Allen. outbreak of disease. Timely diagnosis of a specific “Clostridial Diseases.” The Merck Veterinary disease can decrease the likelihood of more death loss Manual. 11th ed. Kenilworth: Merck & Co., Inc., in the herd. 2016. pp. 601-612. Print.
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HEIDI WARD, DVM, PhD, is assistant professor and veterinarian Issued in furtherance of Cooperative Extension work, Acts of May 8 and with the Department of Animal Science, University of Arkansas June 30, 1914, in cooperation with the U.S. Department of Agriculture, System Division of Agriculture, Little Rock. EREMY POWELL, Director, Cooperative Extension Service, University of Arkansas. The DVM, PhD, is professor, Department of Animal Science, University of University of Arkansas System Division of Agriculture offers all its Arkansas, Fayetteville. Extension and Research programs and services without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action Equal FSA3073-PD-12-2017RV Opportunity Employer.