Coccidiosis

Coccidia are protozoal parasites (Eimeria species) living in the small and large intestinal walls of animalswith the potential to cause disease under certain conditions. They are host-specific, which means that poultry coccidia do not infect ruminants, and cattle coccidia are different from those which infect sheep and goats. Coccidiosis is the disease caused by coccidian infestation.

Coccidiosis is most common in young animals that have not yet become immune, but can also occur in older animals in conditions of over-crowding, or during periods of stress.

Conditions under which coccidiosis is likely to occur

Coccidiosis is likely to occur in:

• young calves, lambs and kids that have not yet developed an immunity or resistance
• animals in poor condition (low body weights at weaning)
• warm and wet areas, especially if stock density it high
• animals confined to small areas, especially if stock density is high
• feed or watering points contaminated with faeces
• stressful conditions, such as weaning, cold weather or poor nutrition.

Identification and diagnosis

Clinical signs that would lead a producer to suspect coccidiosis include the following:

• foul-smelling, profuse scouring with or without blood in the faeces
• straining
• pale gums and membranes around the eyes (anaemia).

Coccidiosis can be confused with gastrointestinal worm infestation. If worms are suspected but animals continue to scour after drenching, consult a veterinarian for an accurate diagnosis of the problem. Coccidian oocysts (‘eggs’) can be identified when a microscopic faecal worm egg count is done.

Prevention

An integrated approach to prevent coccidiosis should consider the following:

• reducing faecal contamination of the environment, especially when young animals are held in confined areas
• minimising stress on young animals by using low stress handling techniques and ensuring nutrition is adequate
• in tropical and subtropical areaswhere there has been a previous coccidiosis problem in calves, feeding a ration or supplement containing an anticoccidial when weaners are held in damp yards or confined for more than a week
• raising feed and water troughs to prevent faecal contamination.