PATHOLOGY Department of Pathobiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Intestinal Cryptosporidiosis in Turkeys in Iran M. J. Gharagozlou 1,5 , O. Dezfoulian 1 , S. Rahbari 2 , S. Bokaie 3 , I. Jahanzad 4 and A. N. E. Razavi 4 Addresses of authors: 1 Department of Pathobiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran; 2 Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran; 3 Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran; 4 Department of Pathology, Faculty of Medicine, University of Medical Sciences of Tehran, Tehran, Iran; 5 Corresponding author: Tel.: 00982122561872; fax: 00982166933222; E-mail: mojavadgh@yahoo.com With 5 figures and 1 table Received for publication September 26, 2005 Summary Naturally occurring cryptosporidiosis is reported in turkey poults suffering from diarrhoea and unthriftness in Iran. His- tological and ultrastructural studies revealed high number of Cryptosporidium developmental stages mainly located in the mid and terminal portions of small intestine of the poults. Other portions of the intestinal tract were less frequently infected. Oocyst shedding was detected only in 29% of the histologically positive birds. Based on host species, clinical signs, pathology and tissue location of the parasites, Cryptos- poridium meleagridis was most likely responsible for these infections. This parasite was also reported recently in a child with diarrhoea in Iran. Introduction Cryptosporidium spp. are intracellular and extracytoplasmic coccidian parasites that inhabit the microvillar border of epithelial surfaces of vertebrates (Dubey et al., 1990; Fayer, 1997; Sre´ter and Varga, 2000). Cryptosporidiosis in birds was first recorded by Tyzzer in 1929, and three valid species Cryptosporidium meleagridis. Cryptosporidium baileyi and Cryptosporidium galli were described from avian hosts in the past decades (Sre´ter and Varga, 2000; Morgan et al., 2001; Ryan et al., 2003). Cryptosporidium meleagridis para- sitizes the small intestine causing diarrhoea and unthriftness (Goodwin et al., 1988). Cryptosporidium baileyi inhabits the respiratory tract and bursa of Fabricius and can be responsible for respiratory disease (Egyed et al., 2002). Cryptosporidium galli infects the proventriculus of birds and might be responsible for diarrhoea (Ryan et al., 2003). On the basis of the literature reports, cryptosporidiosis is a rare disease in turkeys, and two valid species, C. baileyi and C. meleagridis were detected in this host species (Fayer, 1997; Sre´ter and Varga, 2000). Respiratory cryptosporidiosis caused by C. baileyi (Hoerr et al., 1978; Glisson et al., 1984; Tarwid et al., 1985; Ranck and Hoerr, 1987) and small intestinal cryptosporidiosis caused by C. meleagridis (Slavin, 1955; Bermudez et al., 1988; Goodwin et al., 1988; Wages and Ficken, 1989; Tacconi et al., 2001) was observed with similar frequencies in turkeys. Herein, we report intestinal and bursa of Fabricius cryptosporidiosis in turkey poults in Iran. Materials and Methods Animals Sixty, 1–12-week-old turkey (Meleagris galopavo) poults showing clinical signs of unthriftness, persistent diarrhoea or both were obtained from rural areas located in the north and west provinces of Iran. Turkeys were kept as small flocks generally consisting of turkeys, chickens and waterfowls. The type of husbandry was conventional and birds were kept under free run condition. Faecal examination Faecal samples were taken from each bird and examined for Cryptosporidium oocysts using Sheather’s sugar flotation (Dubey et al., 1990) and modified Zeihl-Neelsen technique (Henricksen and Pohlenz, 1981). Pathology and histopathology The poults were killed. The gross lesions were recorded and tissue samples taken from duodenum, jejunum, ileum, caecum, colon, cloaca and bursa of Fabricius were fixed in 10% buffered formalin (pH ¼ 7.2). Selected parts of the formalin-fixed tissues were processed in a tissue processor, paraffin blocks were made, and 5–6 lm thick tissue sections were cut with a microtome. Sections were stained with haematoxylin and eosin. On the basis of the description of Guy et al. (1987), scoring of the severity of infection with cryptosporidia in tissue sections was assessed by using a magnification of 400· as follows. 0: negative; 1: very few (less than three developmental stages per microscopic fields); U.S. Copyright Clearance Center Code Statement: 0931–184X/2006/5306–0282 $15.00/0 www.blackwell-synergy.com J. Vet. Med. A 53, 282–285 (2006) Ó 2006 The Authors Journal compilation Ó 2006 Blackwell Verlag, Berlin ISSN 0931–184X