NADIS disease bulletins are written specifically for farmers, to increase awareness of prevalent conditions and promote disease prevention and control, in order to benefit animal health and welfare.

Farmers are advised to discuss their individual farm circumstances with their veterinary surgeon

Tetanus in Cattle

Tetanus is a fairly common disease occurring in all types of livestock. It is relatively rare in cattle, but cattle can get tetanus and outbreaks of disease can cause very severe losses.

What is tetanus?

Tetanus is a highly fatal disease caused by toxins produced by the bacterium Clostridium tetani. This bacterium is found in the soil and the guts of animals and humans. The disease starts when the organism gets into wounded or damaged tissue as a result of contamination. In the absence of oxygen the bacteria multiply and produce a local infection. As they grow, the bacteria produce poisons (toxins), which spread along the nerves to the brain and cause the clinical signs of tetanus. We don’t know how the toxins are transported or how they produce their effect on the nervous system.

The time between infection and disease can be very short (two or three days) or quite long (four weeks or more), depending on how long it takes for the contaminated area to develop a low level of oxygen (such as by a wound healing over sealing off the tissue from the outside).

The disease is seen in all ages of stock. Calving and castration seem to be the most common procedures linked to the development of tetanus

Clinical Signs

· Stiffness and reluctance to move are normally the first signs

· Twitching and tremors of the muscles

· Lockjaw

· Prominent protruding third eyelid

· Unsteady gait with stiff held out tail

· Affected cattle are usually anxious and easily excited by sudden movements or handling.

· Bloat is common because the rumen stops working

· Later signs include collapse, lying on side with legs held stiffly out, spasm and death.

Diagnosis

· The clinical signs are characteristic and in many cases the only information available for making a diagnosis

· Post mortem investigation is very useful for ruling out other causes of similar disease, such as CCN, staggers or lead poisoning

· Growing the bacterium from the suspected site of infection is a useful finding. However, it is often very difficult to culture Cl. tetani, because the numbers of bacteria are usually small and the site of infection is often hidden

Treatment

· Cattle with early tetanus probably respond to treatment better than most other livestock

· In very early cases very high doses of penicillin may be helpful, particularly if combined with local treatment of the infected site.

· Antitoxin is probably of little value unless given in the very early stages.

· In some cases sedatives and relaxants can aid recovery

· Good nursing is important. Treated animals need dark quiet surroundings with lots of space and plentiful bedding

· It is not worth treating cattle with fully developed tetanus

Prevention

Undertaking surgical procedures (such as castration) properly, in a clean environment, with disinfected instruments and surgical area, will significantly reduce the risk of tetanus. The same rules apply to calving, be as clean as possible and minimise contamination.

Antitoxin can be useful as a short-acting (up to 21 days) preventative if used at high risk times, however on such farms vaccination may be better as a three dose course of vaccination can result in protection for over three years.

Richard Laven PhD BVetMed MRCVS