Psittacine beak and feather disease in 2 free-living great green macaws: a case report and literature review.

Psittacine beak and feather disease (PBFD) is caused by the psittacine beak and feather disease virus (PBFDV; Circoviridae, Circovirus parrot). This disease affects mainly young captive birds, inducing lesions mainly in the skin adnexa and lymphoid organs. Here we report PBFD in 2 free-living great green macaws (Ara ambiguus). The birds were depressed and had lost feathers and body condition. The diagnosis was confirmed by gross lesions and PCR testing in one bird, and by gross and microscopic lesions, PCR testing, viral sequencing, and in situ hybridization in the other bird. Gross lesions in both birds included mild beak discoloration and feather loss. Microscopic lesions in the bird whose tissues were examined histologically included bronchopneumonia and severe lymphoid depletion with intracytoplasmic and intranuclear botryoid inclusion bodies in the cloacal bursa. Sequences of the viral DNA obtained from paraffin-embedded cloacal bursa tissue had 100% nucleotide and 100% amino acid identity with several strains of PBFDV isolated from captive birds in multiple countries. To our knowledge, PBFD has not been reported previously in free-living great green macaws.