Coccida is a protozoan parasite of the intestines that commonly causes diarrheal disease in young cattle from about 1-2 months up to 2 years. During the reproductive phases of the organism’s life cycle, the mucosal surfaces of the intestines are disrupted and may result in bloody diarrhea and straining in severe cases. Most cattle experience infection with one or more coccidian species during the first year of their life. Therefore, finding a few oocysts (coccidian eggs) in a fecal exam on a sick calf does not necessarily justify a diagnosis of coccidiosis in the place of a thorough physical exam. Subclinical and chronic cases of coccidian infections manifest as unthrifty calves with fecal staining under their tails. Feed inefficiency in otherwise healthy looking calves could be the result of low level infections. The most common manifestation of the disease is watery diarrhea that lasts several days and may or may not contain blood. Dehydration can result in death from severe acute forms of the disease and weight loss may be significant enough that it permanently stunts calves that recover. Nervous signs of the disease can occur, but have only been associated with calves during midwinter in Canada and the Northwestern United States.
Control of the disease is focused on management practices that provide a clean environment with minimal fecal contamination at feed and water sources. Housing should be adequate and provide good ventilation. Furthermore, adopting an “all-in, all-out” system prevents co-mingling of different age groups that could expose younger animals to higher pathogen loads and stress. In the face of an outbreak, it is a good idea to isolate affected animals and may be necessary to mass medicate groups. Electrolytes are vital to keeping calves hydrated. Secondary bacterial enteritis and pneumonia may result from immune suppression, which will require treatment as well.
If you suspect an outbreak of coccidia, bring a fecal sample by the office or have us take a look at the calf to determine if a secondary infection may need to be addressed as well.