ABSTRACT
Cryptosporidiosis in birds manifests itself as respiratory disease, enteritis, or renal disease. Two other species of Cryptosporidium have been named from birds: Cryptosporidium anserinum and Cryptosporidium tyzzeri. Only in a few birds can parasites be found in the respiratory tissues. Conjunctival infections occur in some birds when oocysts are placed directly on the conjunctival sac. Experimental studies indicate that most attempts to transmit Cryptosporidium baileyi isolated from chickens to other birds are successful, with the exception of bobwhite quail. Clinical respiratory disease occurred only in the 2- and 14-d- old birds. Naturally occurring cryptosporidiosis in birds manifests itself in three clinical forms: respiratory disease, enteritis, and renal disease. Most studies on experimentally induced cryptosporidiosis in birds have been done with C. baileyi isolated from chickens. Prevalence data indicated a higher incidence of cryptosporidiosis in chickens in Georgia. Renal cryptosporidiosis has been reported in black-throated finches, jungle fowl, and chickens.
