by Karoline Inong

Created on: May 23, 2009   Last Updated: May 24, 2009

Tetanus, also known as lockjaw, is common and highly fatal among sheep and goats. Tetanus is caused by spores of the bacterium Clostridium tetani. These spores can remain infectious for years in soil and feces.

Often times sheep get wounds from routine process such as castration, ear-marking, tail-docking, and dehorning. Wounds then can get infected by contamination from the dirt, dust or feces. Infection, however, can occur through non-surgical wounds such as dog bites and shearing cuts.

The incubation period for Clostridium tetani, is typically between three days and three weeks. In this time It produces two toxins, tetanolysin and tetanospasmin. Tetanolysin hemolyzes erythrocytes while tetanospasmin attacks the nervous tissue. Majority of the clinical effects of tetanus are because of the neurological effects of tetanospasmin. This toxin penetrates the nerves around the wound. It then travels to the spinal cord and the brain where it cause the nerve cells to produce exaggerated and uncontrollable muscle spasms.

The clinical signs of tetanus in sheep are typically appear three to ten days after injury. In the early stages, symptoms tend to be ears erect, stiff and elevated tail, head extended, eyes appear anxious but cannot move, difficult walking due to legs being rigid and extended, and often times sudden noise or physical contact brings along violent muscular contractions. As tetanus progresses in a sheep you may see that they are unable to walk and cannot get up, their jaw locks, and their nostrils may become dilated. Tetanus in sheep has the mortality rate of 100% and sheep often times die within ten days after becoming infected.

To treat sheep that have tetanus, you need to care for the local wound on the sheep. You can do this by correctly administering large doses of anti-toxin and penicillin. However, it is fairly a complex procedure so you should contact your veterinarian as soon as you suspect that one of your sheep has tetanus. Typically there is a poor response to the treatment and can be considerably expensive.

Tetanus can be prevented in your sheep herds and therefore is cheaper than if they were to contract tetanus. In preventing tetanus, you must always remember cleanliness. It is important that you make sure that any surgical instrument that you use should be thoroughly clean before and after use and they must also be kept clean during the procedure. Using temporary yards in grassy areas also help along with watering down yards to decrease the amount of dust. Also make sure when marking, the operators should make sure that the lambs leave the cradle so that they land on their feet and that the wound is not contaminated by dirt. However, even though you may tried to maintain cleanliness in your best effort, many times the wound is contaminated so you should also implement a vaccination program.

In vaccinating your sheep, the tetanus vaccine contains two doses at least four weeks apart along with an annual booster. After the first dose of the tetanus vaccine there will be some temporary immunity that will appear 9-14 days after but it will quickly fade. However, a single vaccine of tetanus in no means can prevent sheep from getting tetanus.

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