A few weeks ago, I saw a case of progressive paralysis in a calf. The calf was down, bloated and had a temperature over 40 degrees. The signs had come on over 24 hours and had started as just being wobbly when moved. This animal had been vaccinated with its first 5 in 1 vaccine two weeks before and had been castrated earlier that week.
These signs were consistent with Tetanus or LockJaw. Tetanus is caused by the bacterium Clostridium Tetani which is found in the soil and in animal faeces. The bacterium enters through a deep wound and then releases a toxin called tetanospasmin which slowly spreads up the nerves to the central nervous system.
Symptoms show up 7 to 14 days after entering the wound and symptoms include:
• Muscle stiffness
• Spastic muscle contractions
• Contraction of the jaw muscles so unable to eat
• Third eyelid up
• Respiratory arrest and death
We treated the animal by relieving his bloat, giving high doses of penicillin, Tetanus antitoxin and supportive care but unfortunately the damage spread to the diaphragm and it died.
The 5 in 1 vaccines contain Clostridium tetani, as well as the clostridial bacteria that cause Blackleg, Pulpy kidney, Black disease, and malignant oedema. 6 in 1 also contains Clostridium sordelli, an organism believed to cause sudden death.
In cattle and sheep, two doses a month apart plus a single annual booster will provide lifelong immunity against Tetanus and Blackleg, but the other diseases need yearly boosters. Animals are susceptible to Tetanus if they have only had one injection, so we recommend giving two doses before castration, and this can start as early as six weeks old.
If ewes haven’t previously been vaccinated, two doses of vaccine at mating and then four weeks before lambing will protect them and their lambs for the first six to eight weeks of their lives.