Controlling Clostridial Diseases in Cattle

by Nolan R. Hartwig, DVM, Department of Veterinary Diagnostic & Production Animal Medicine,Iowa State University

Clostridia are a group of anaerobic spore-forming bacteria that can live in the environment for many years. They cause a variety of conditions in cattle, including enterotoxemia, blackleg, and malignant edema. They are involved in the sudden-death syndrome in feedlot cattle. When the costs of prevention and control are considered, losses to the cattle industry are significant. Losses in individual herds may be high if effective diagnostic and preventive procedures are not employed.

Blackleg is an acute condition, usually of pastured cattle younger than two years of age. It is characterized by an infection of the heavy muscle masses. Affected cattle are usually found dead on pasture. On post mortem examination, dark-colored lesions are found in the heavy muscle masses, often of the rear leg. The spores of the causative organism, Clostridium chauvoei, contaminate the soil and are picked up by grazing cattle. The spores vegetate and invade the heavy muscle masses by mechanisms that are not fully understood. Death occurs in a few hours. Blackleg occasionally occurs in feedlot cattle. Many farms, pastures, and flood plains are known to be high risk or “blackleg” pastures. Blackleg vaccines are highly effective when properly administered.

Malignant edema is caused by infection of wounds or surgical sites with Clostridium septicum. Infection of the scrotum after castration or of the vulva and vagina after difficult calving are common infection sites. Massive fluid-filled swelling at the site of infection is characteristic of malignant edema. In addition to vaccination, aseptic surgery and proper wound treatment help prevent this disease.

The cause of the so-called “sudden death syndrome” in feedlot cattle has been controversial. On post mortem examination, Clostridium perfringens, Cl. sordelli, and Cl. novyi may be found. Most pathologists and feedlot clinicians believe these organisms are opportunists and invade the circulation following clinical or subclinical acidosis, entering the circulation through small ulcers or erosions in the rumen. Vaccination and sound feedbunk management prevent most cases of sudden death syndrome. Losses may be severe when cattle are fed a high energy ration without adequate adjustment time. Sudden death is a frequent problem in feedlot cattle on self-feeders. Sudden death syndrome due to Clostridial organisms should not be confused with acidosis due to rapid ingestion of large amounts of concentrate. Losses are also common when environmental temperatures are extremely warm; resulting in variable feed intake. Vaccination upon entry into a feedlot may be helpful, but routine re-vaccination is seldom recommended. Control of sudden death in feedlot cattle depends in large measure on regular feed intake resulting from good feedbunk management.

Enterotoxemia is a disease, primarily of young calves caused by Clostridium perfringens. It is characterized by sudden death, diarrhea that may be bloody, or a profuse diarrhea that may not always result in death. In the peracute form, convulsions and other central nervous symptoms may occur. Cl. perfringes may play a role in less acute forms of calf diarrhea. Over-consumption of large amounts of milk, inadequate colostrum intake, chilling and stress are conducive to development of enterotoxemia.

Organisms that cause blackleg, malignant edema, enterotoxemia, and other causes of sudden death due to Clostridia make up the clostridial group or “7-way” vaccine. The seven organisms are: Clostridium chauvoei, septicum, perfringens B, C, and D, sordelli, and novyi. An eighth organism, Cl. hemolyticum, causes “red water” disease. Red water occurs most commonly in some areas of the West, and is characterized by passing of red, bloody urine. If untreated, death loss can be high. In endemic areas, eight-way vaccines containing this organism are often used.

Clostridia vaccines usually are given to calves in late spring or early summer to prevent blackleg. Feeder calves should be vaccinated in preconditioning programs or when processed for entry into backgrounding programs or feedlots. Many breeders re-vaccinate heifers prior to breeding. Some veterinarians recommend vaccinating heifers prior to calving if diagnosed losses due to enterotoxemia have been high in that operation.

Clostridia vaccines are major causes of injection site lesions. Improper use is a major cause of injection site lesions and is a major concern for the beef cattle industry. Clostridia vaccines should be given subcutaneously, according to label directions. They should never be given in the heavy muscle masses of the rear quarter, even in young, nursing calves. Scarring caused by these vaccines may persist permanently in the muscles, resulting in scarring, injection site lesions, and carcass trim. Two ml. (cc) dosage vaccines are widely available and reduce the amount of injection site damage. Many veterinarians feel that vaccinating cattle while wet increases the risk of tissue reaction and infection at the inject site. Compounds called adjuvants are included in Clostridia vaccines. Adjuvants present the organisms or antigens to the animal’s immune system over a period of time, greatly increasing the immune response. Adjuvants, however, are somewhat irritating and cause much of the tissue reaction commonly associated with Clostridia vaccines. Manufacturers have made great progress in reducing the amount of irritation while maintaining the effectiveness of adjuvants. Consult your herd veterinarian on choice of vaccines, routes of administration, timing of administration, and how to avoid injection site lesions.