Clostridial diseases in sheep: Know the enemy

Clostridial diseases, caused by Clostridium spp. bacteria, are among the leading causes of sudden, unexpected deaths in sheep, often with few visible signs.

- By Koos du Pisanie

According to Dr Roland Larson, a veterinarian from Graaff-Reinet, these bacteria are ubiquitous in nature and can even persist in soil due to their ability to thrive in anaerobic (oxygen-poor) environments. They also inhabit the intestinal tract of healthy animals, making them extremely difficult to eliminate or avoid.

Clostridial diseases are generally classified into three groups, based on disease signs and progression: the enterotoxic group primarily inhabits the gastrointestinal tract and produces toxins; the neurotoxic group impacts the nervous system as a result of the toxins the bacteria produce; and the gangrenous group causes severe tissue and muscle damage.

Dr Hanré Ferreira, veterinarian and technical support manager at Virbac, explains that although Clostridium bacteria are widespread, they multiply rapidly under favourable conditions like when animals have a high nutritional intake or following deworming. Once they begin to proliferate, they release toxins that damage various body systems, leading to clinical signs and, often, death.

Most prevalent diseases

Clostridium spp. includes several bacterial species that cause a wide range of diseases in sheep:

• Enterotoxic group: The most prevalent clostridial disease in this group is pulpy kidney, followed by blood- and redgut.

• Neurotoxic group: The predominant diseases are tetanus and botulism.