Birds *

Cryptosporidiosis is one of the most prevalent parasitic infections in domesticated, caged, and wild birds, and the parasite has been reported in more than 30 avian species worldwide, belonging to orders Anseriformes, Charadriiformes, Columbiformes, Galliformes, Passeriformes, Psittaciformes, and Struthioniformes. Only three avian Cryptosporidium spp. are recognized: Cryptosporidium meleagridis, Cryptosporidium baileyi, and Cryptosporidium galli. These three Cryptosporidium spp. can each infect numerous birds, but they differ in host range and predilection sites. Two other species of Cryptosporidium have been named from birds: Cryptosporidium anserinum from a domestic goose and Cryptosporidium tyzzeri from chickens. Naturally occurring cryptosporidiosis in birds manifests itself in three clinical forms: respiratory disease, enteritis, and renal disease. Usually only one form of the disease is present in an outbreak. Although three Cryptosporidium species are considered to be valid in birds and a number of avian genotypes have been identified, most reports of natural infections have not provided enough information to conclusively determine the species or genotype involved.