Cryptosporidiosis

Cryptosporidiosis usually causes diarrhoea in calves between one and four weeks of age.

Etiology

Cryptosporidia are small protozoan parasites. Cryptosporidium parvum is commonly isolated in cattle. The parasites complete their life-cycle in gastrointestinal epithelial cells. In young animals the life-cycle is completed within 3-4 days.

Pathogenesis

Cryptosporidia parasites invade the enterocytes of the distal small intestine and large intestine. Villous atrophy and fusion lead to malabsorption resulting in diarrhea. Pathology is usually worse in the distal small intestine.

Clinical Signs

Faecal consistency varies from loose to watery. Tenesmus due to colitis may be seen. Disease usually has a high morbidity and low mortality. Some cases may result in chronic diarrhoea with resulting cachexia.

In many cases cryptosporidia is seen with other diseases, particularly rotavirus. In these cases the severity of the disease increases with more affected calves.

Treatment and Prevention

Halocur, active ingredient halofuginone, is effective for the treatment and prevention of cryptosporidia and can be dosed to neonatal calves.

Cryptosporidia are very resistant to disinfectants and can survive for long periods in the environment. Good management and hygiene are thus vital for control.

rotavirus

Cryptosporidium seen in a faecal wet prep