News & Advice

Clostridial diseases in Sheep and Cattle

Nov 2, 2018 | Beef cattle, Dry stock, Dry stock animal health & welfare, Grazing youngstock, Sheep

Alise Yates, Veterinarian, Anexa Vets Ngatea

Many younger farmers may not have seen some or all of the common clostridial diseases present in New Zealand. This is because vaccination is so effective at preventing and minimizing losses from these deadly diseases. Those of us that have seen these often recognize them as sudden death as the course of the disease can be so rapid. Despite the fact we don’t commonly see clostridial disease anymore; vaccination is still a crucial part of the control. This is because the bacteria that cause these diseases form spores that are resistant in the environment, so every animal is likely to experience a challenge in their lifetime.

The most commonly seen clostridial diseases in New Zealand are:

  • Tetanus – bacteria enter deep wounds (e.g. from docking or shearing) and hide in damaged tissue where there is little Oxygen.. Clinical signs are seen 10 to 14 days after the injury and live animals look rigid as their muscles spasm however, the dead animal looks normal.
  • Pulpy kidney – usually seen in well fed well grown lambs as sudden death. Externally there are no signs but sometimes a diagnosis can be made from post mortem. This is occasionally seen in cattle.
  • Black leg – this is most commonly seen in cattle 6 to 24 months of age. Damage to tissue from bruising or wounds allows the spores to proliferate in the tissue. Often death is seen without signs of disease but on post mortem gas under the skin and muscle damage can be found.
  • Malignant oedema – this is similar to black leg in its presentation but invasion into the tissue is through wounds. It is most commonly seen as sudden death.

Due to the speed of the clostridial disease process, prevention is essential. Treatment is often unreliable when disease can be identified but more commonly cases are seen as sudden death. Vaccination for clostridial diseases is really cost effective and losses of even small numbers of stock will cover the cost of vaccination.

The cattle vaccination schedule is 2 x 2ml doses, 4 weeks apart. If a follow up vaccination is given 12 months later, then they are considered to have lifelong immunity against tetanus and black leg.

The sheep vaccination schedule is 2 x 1ml dose, 4 weeks apart. If a follow up booster is given 12 months later, then they are considered to have lifelong immunity. In pregnant ewes that have been vaccinated previously a booster should be given within four weeks of the expected lambing. This should help protect the lambs through colostrum for the first six to eight weeks of life.
Immunity develops about 10 days after vaccination. For more information and to plan on which vaccination is best for your farm, contact your local Anexa Vet.

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