Respiratory cryptosporidiosis in a peacock chick.

Respiratory cryptosporidiosis was diagnosed in a 2-week-old peacock chick, whose symptoms were a gurgling respiration, coughing and sneezing, and a serous oculonasal discharge. Light microscopy detected cryptosporidial-like organisms attached to the surface of conjunctival, nasal-sinus, and tracheal-epithelial cells, and electron microscopy demonstrated stages typical of cryptosporidial trophozoites, schizonts, and oocysts. About 30 other in-contact peacock chicks also developed the same clinical symptoms, and all died despite treatment with oxytetracycline HCl at 200 ppm in the drinking water.