Fowlpox is one of the oldest diseases reported in birds. The causative genus Avipoxvirus affects ~232 domestic and wild species. We present herein the history, clinical findings, and macroscopic and histologic lesions caused by a clade C poxvirus in an exotic psittacine breeding colony in southern Brazil. Clinical signs included yellow nodular lesions at the commissure of the beak and on the periocular skin, loss of appetite, and death. Fifty birds were autopsied, and fragments of periocular skin, tongue, and trachea were examined histologically, which revealed hyperkeratosis associated with eosinophilic intracytoplasmic inclusion bodies. Tracheal fragments and periocular skin were subjected to nested PCR and phylogenetic analyses. The sequenced strain showed 99.58% identity with the nucleotide sequences of Avipoxvirus strains AY53011, KC018069, AM050383, and AM05382 isolated from birds in Germany, United States, and United Kingdom. The strain was grouped under clade C, which represents isolates exclusively from the Psittacidae family. The infection caused by clade C Avipoxvirus in the exotic psittacines examined ( Platycercus sp. and Psephotus haematonotus) demonstrates the circulation of this clade in this breeding colony.
Keywords: Avian diseases; Avipoxvirus; Brazil; psittacine birds; smallpox.