عنوان مقاله [English]
Crytosporidiosis is a parasitic disease caused by the cryptosporidium protozoan in the vertebrate animal. This parasite in livestock special ruminants causes diarrhea syndromes in infants. The main sources of the parasite spread are infectious feces and the host mouth. The purpose of this project was to isolate and identify the cryptosporidium species by morphological indices in diarrheic calves in order to detect and control the disease. According to the method of Casemore et al., purification of oocysts from feces using flotation technique was carried out. Staining with modified Zeil nelson method (Henrisksen method) and identification with diagnostic keys was done. Cryptosporidium parvum alone causes clinical disease in young calves; the latent infection time is 3 to 6 days. Cryptosporidium muris, C. Andersoni and C. ryanae have been reported in weaned calves, and C. Andersoni has been also observed in adult cattle. The total of 150 cattle fecal samples were randomly collected from Alborz province. 60 out of 150 (40%) calf diarrhea positive samples were detected by modified Zeil nelson method staining. In all fecal samples from calves without diarrhea, the oocyst was not observed. In calves below one month, especially in the first two weeks, 40% of the diarrheic samples were infected. This protozoon is a zoonotic and opportunistic parasite and, in Iran, it has been reported from various species like poultry, cattle, sheep and goats and it may cause significant economic losses which need much more attentions.