Microsporidiosis has been sporadically documented in birds.1,2 Intestinal microsporidiosis was diagnosed in a European goldfinch (Carduelis carduelis), a lovebird (Agapornis roseicollis), and a canary (Serinus canaria) from different aviaries and concurrently affected with mycobacteriosis, macrorhabdiosis and a chlamydial-like infection of enterocytes, and poxviral glossitis, respectively. All birds presented with weakness, weight loss, and/or ruffled feathers. Enterocytes in the small intestine contained colonies of gram- and stamp-positive, oval to elliptical microorganisms measuring 2x1–1.5 µm and located within parasitophorous vacuoles in the apical cytoplasm that were reminiscent of microsporidia. The cloaca was also affected in the canary. The results of PCR and sequencing in all three birds were consistent with microsporidiosis due to Encephalitozoon hellem infection. Although concurrent infections were the main disease processes, microsporidiosis likely contributed to exacerbated catabolism and possibly to death. Encephalitozoonosis has been rarely reported in passerine birds.1 The occurrence of microsporidiosis with one or more viral, bacterial or fungal infections suggests underlying immunosuppression.
1. Gelis S, Raidal SR. Microsporidiosis in a flock of tricolor parrot finches (Erythrura tricolor). Vet Clin North Am Exot Anim Pract. 2006;9:481–486.
2. Sak B, Kasicková D, Kvác M, Kvetonová D, Ditrich O. Microsporidia in exotic birds: intermittent spore excretion of Encephalitozoon spp. in naturally infected budgerigars (Melopsittacus undulatus). Vet Parasitol. 2010;168:196–200.