Giardiasis and Cryptosporidiosis M . E . Olson

Giardia duodenalis and Cryptosporidium parvum are parasitic protozoans and infections are common in domestic ruminants. Infections can lead to moderate to severe diarrhea with occasion mortalities. Clinical disease with Cryptosporidium parvum occurs in calves between 1 and 3 weeks of age lasting 1-2 weeks in duration. Giardiasis is observed in calves older than 3 weeks of age and is chronic. These diseases have tremendous ability to be transmitted from animal to animal and from animal to humans. These infections have led to a significant environmental and public health concern. Cryptosporidium muris infects older calves and may impair rate of gain in feedlot cattle and milk production in dairy cattle. Giardia infections can be treated with benzimidazoles but there are currently no effective treatments for cryptosporidiosis. Clearly, effective methods need to be employed to treat, prevent or control these diseases.