Bulgarian Journal of Veterinary Medicine (2009), 12 , No 1, 55− 61 EPIDEMIOLOGY OF CRYPTOSPORIDIUM INFECTION IN OSTRICHES (STRUTHIO CAMELUS) IN IRAN M. A. BEHZADI 1 , S. M. RAZAVI 2 , H. YAZDANPOOR 2 , A. MIRZAEI 1 , A. TAMADON 1 & M. JAVDANI GANDOMANI 1 1 Department of Clinical Sciences; 2 Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz; Iran Summary Behzadi, M. A., S. M. Razavi, H. Yazdanpoor, A. Mirzaei, A. Tamadon & M. Javdani Gandomani, 2009. Epidemiology of Cryptosporidium infection in ostriches (Struthio camelus) in Iran. Bulg. J. Vet. Med., 12, No 1, 55−61. Avian cryptosporidiosis has been reported in more than 30 species of birds. To date, the species in- fecting birds are C. baileyi, C. galli and C. meleagridis. In this study, the prevalence of Crypto- sporidium in southern Iran and the morphological characteristics of oocysts are described. Crypto- sporidium oocysts were found in the faeces of 21 of 75 examined ostriches (28%) from 3 farms in southern Iran. The genus identity of the oocysts was confirmed by morphology. The mean (±SD) size of 102 oocysts was 4.4±1.14 × 3.9±0.96 µm (range 3.8–8.6 × 2.9–7.6 µm) with a shape index (length/width) of 1.13±0.13 (range 1.0–1.33). Data analyses indicated no significant effect of ostrich population on the prevalence of Cryptosporidium infection. Based on the odds ratio, an increase of 1 m 2 space for each ostrich decreased the prevalence of disease by a factor of 0.99. Stressing conditions leading to immunosuppression or poor husbandry practices related to feed, water or hygiene, were apparently acting as predisposing factors to the onset of cloacal prolapse or other pathology related to the Cryptosporidium spp. found in this experiment, since the improvement in husbandry practices has stopped the mortality and clinical signs, even in the presence of the parasite. To our knowledge, this is the first report of Cryptosporidium spp. occurrence in ostriches in Iran. Key words: Cryptosporidium spp., Iran, morphology, ostriches INTRODUCTION Protozoa of the genus Cryptosporidium are apicomplexan parasites that complete their biological cycle in the surface of epithelial cells of the digestive and respi- ratory systems of a wide variety of verte- brates (Xiao et al., 2004). Once consid- ered rare and irrelevant, Cryptosporidium spp. are now known to be important pathogens, with a widespread distribution in livestock, wildlife, and humans (Fayer, 2004). Transmission is through the faecal- oral route, following direct or indirect contact with Cryptosporidium oocysts via animal-to-animal, waterborne, foodborne or airborne contact (Fayer, 2004). Crypto- sporidiosis has been reported in more than 30 species of birds in many coun- tries (Lindsay & Blagburn, 1990a; Sréter & Varga, 2000; Morgan et al., 2001). The parasite has been found in gastroin- testinal, respiratory, urinary, pancreatic, and biliary tracts of hosts, and has been associated with disease (Gajadhar, 1993). Cryptosporidiosis is a significant cause of intestinal and respiratory tract disease in domestic chickens and turkeys (Fletcher