Parasites of the gennus Cryptosporidium infect several animal species.The disease resultant is the criptosporidiosis, an important zoonosis spreaded worldwide. In poultry, the infection has been reported in several species. This study goal was to identify the parasite presence in 208 bursa of Fabricius samples, 208 intestine and 208 of trachea, collected at chicks (Gallus gallus sp) of different ages, killed at three farms in Santa Maria city, Rio Grande do Sul State, Brazil. Three printings of each sample were done,on glass slides colored through the Ziehl Neelsen technique modified with Dimetil Sulfóxido (DMSO), Ziehl Neelsen modifed by Henriksen and Pohlens (HP), Ziehl Neelsen (ZN) and Kinyoun (K), completing 1872 printings analyzed in optical microscopy (1000 x). At this final number, at the different colorations done, oocysts of the parasite Cryptosporidium sp. were viewed in 18 trachea printings, 42 of bursa de Fabricius and 29 of intestine, resulting positive, 89 printings. From these 89, 44 were identified through the technique DMSO, 32 through HP, three through ZN and 10 through K. Cryptosporidium sp. parasites oocysts were found with more frequency from printings of bursa the Fabricius. The coloration method, of those utilized, was the one which had the better visualization of the oocysts was the DMSO.
Cryptosporidium sp.; chicks; intestines; bursa of Fabricius; trachea