Background: Studies were conducted on prevalence and distribution of Cryptosporidium parvum in calves aged below 3 months in University of Eldoret farm and other farms in Uasin Gishu County, Kenya for a period of six months in 2009.During the study period, 241 and 80 dung samples were collected from diarrhoeic and non-diarrhoeic calves respectively and microscopically examined. Stool from the livestock was analysed for the presence of Cryptosporidium parvum oocysts by Zinc sulphate floatation technique followed by Ziel-Neelsen staining method. Results: Prevalence of Cryptosporidium parvum in diarrhoeic calves was 75%, 70.6%, 62.5% and 38.5% for Kobilo, Sirikwa B, University of Eldoret and Sirikwa A farms respectively. Prevalence of Cryptosporidium parvum in the non-diarrhoeic calves was 45%, 15%, 10% and 5% for the same farms respectively. Conclusions: Cryptosporidium parvum was positively related to the diarrhoeic status of the calves (p< 0.05). The prevalence of Cryptosporidium parvum oocysts was significantly higher in diarrhoeic animals than in non-diarrhoeic ones. It was concluded that the overall prevalence and distribution of Cryptosporidium parvum was associated with diarrhoea in calves. However, there is need for a long term study to elucidate the effect of other risk factors for Cryptosporidium parvum infection in calves, and the occurrence of diarrhoea in relation to cryptosporidiosis and other infections. Keywords: Cryptosporidium parvum, prevalence, diarrhoea, calve
