Cryptosporidiosis is an important zoonotic gastrointestinal disease caused by infection with cryptosporidium protozoa, predominately C. parvum. C. andersoni, C. baileyi and C. meleagridis have also been isolated from outbreaks of disease incidents in cattle. Cryptosporidiosis is characterized by the the onset of scour in young calves. Scouring calves have been found to shed large amounts of oocysts in their feces. Adult cattle and recovered animals will continue to shed oocysts, but in smaller amounts.
C. parvum is transmitted by fecal-oral route. Calves become infected through eating, drinking, or licking feces shed by infected animals or feed, water, soil, equipment or personnel which have been contaminated with oocysts of cryptosporidium.
The incubation period on average in calves is 4 days.