Clostridial diseases describe a group of diseases caused by bacteria from the clostridal family, and include diseases such as blackleg, bacillary haemoglobinuria, black disease, malignant odema, tetanus and botulism.

These often present as sudden deaths, where animals have no history of being sick. Many of these diseases are specific to certain farms and indeed fields within farms, as the bacterial spores that cause these conditions are in the soil in these fields.

They are also found in rotting animal tissues, stagnant water and in the intestines of healthy animals. They are anaerobic bacteria, so they prefer an environment with no oxygen. They form spores so they can survive environmental conditions such as cold which would kill off other bacteria.

What do they look like?

Often there are no presenting signs with all of the clostridial diseases, and animals are found dead.

If found early, animals with blackleg (Clostridium chaovei) can present with severe lameness and high temperatures. Usually one leg or quarter is affected, but remember this condition can affect any muscle, including the heart, diaphragm or the tongue. Gas builds up in the affected muscle, giving it a feel of crepitus.

Malignant oedema (Clostridium septicum) affects muscle tissue similar to blackleg, causing swelling with a crepitus feel.

Black disease (Clostridium novyi) causes focal areas of necrosis (dead tissue) within the liver, and often occurs secondary to damage caused by liver fluke.

Clostridum perfingens causes enterotoxaemia as a result of the proliferation on the bacterium in the gut. It is a common cause of sudden death in neonatal lambs especially and the bowel has a reddened appearance.

Bacillary haemoglobinuria (Clostridum haemolyticum) causes red or black coloured urine. This condition seems to be confined to the north Cork/Limerick area in Ireland.

Botulism (Clostridium botulinum) is a flaccid paralysis of the hind limbs, where affected animals become recumbent, but stay bright and alert around the head.

Tetanus (Clostridium tetani) is a rigid paralysis. This condition is associated more with horses, but can also affect cattle.

What are the predisposing factors?

Generally speaking, clostridial diseases affect younger animals which are thriving well.

The disease occurs when animals are at pasture, rather than in housed animals.

As they prefer anaerobic conditions, they are often introduced via a wound (tetanus), bruised muscle (blackleg) or damaged tissue (fluke damage to liver in black disease).

Outbreaks of botulism have been associated with the spreading of poultry litter, although other conditions may also predispose to it. The presence of rotting chicken carcases is the crucial factor.

Treatment and prevention

Antibiotic treatment may be given to affected animals, but the prognosis for affected animals is generally poor. Prevention by way of clostridial vaccine is a highly effective method of control for all the clostridial diseases apart from botulism.

  • As there are a wide variety of clostridial diseases out there, a vaccine which covers several types of clostridial disease is the preferred choice.
  • A minimum of two injections are required four to six weeks apart. An animal which received a single vaccine cannot be considered fully vaccinated.
  • If the vaccine is not used immediately after purchase it should be stored in a fridge. Any vaccine which has been opened but not used by the end of the day should be discarded.

    • Vet’s corner: Clostridial diseases in cattle