Abstract: Microsporidian parasites belonging to the protozoan phylum Microspora are reported to cause disease in the majority of invertebrate phyla and all 5 classes of vertebrates. The organisms cause serious diseases in silkworms, amphibians, reptiles, and fish, and are becoming of increasing importance in human and veterinary medicine. The microsporidian parasite Encephalitozoon cuniculi is commonly found in rodents and laboratory rats, where reported incidence varies from 5 to 75%. Microsporidian infections have been reported in humans and may become of even greater importance in immunocompromised patients in the future. 1,5,8 Four confirmed avian cases have been in lovebirds and one case has been reported in a parrot