Psittacine Beak and Feather Disease (PBFD) is known to occur in a wide range of psittacine species, however there are no scientific or credible anecdotal reports of PBFD occurring in the cockatiel (Nymphicus hollandicus) despite it being one of the world's most commonly kept companion bird species. Consequently this has resulted in speculation that the species may have some innate resistance to beak and feather disease virus (BFDV) infection. To investigate this we conducted a survey of cockatiels (n=88) at commercial aviaries to investigate whether BFDV infection occurs in cockatiels and found that all birds were virus-free by PCR and haemagglutination assay (HA) and had no detectable antibody titre by haemagglutination-inhibition (HI) assay. In addition to this, we sequenced the genome of two BFDV isolates obtained from diseased cockatiel feathers and performed cross-reactivity assays using virus eluted from these feathers and sera from naturally immune psittacine birds. Serological cross-reactivity results and phylogenetic analysis of the nucleotide sequences indicated that the cockatiel virus isolates were serologically and genetically different to other BFDV isolates. This is the first paper to report evidence of an antigenically distinct BFDV in psittacine birds.
Shearer, P., Bonne, N., Clark, P., Sharp, M., & Raidal, S. (2008). Beak and feather disease virus infection in cockatiels (Nymphicus hollandicus). Avian Pathology, 37(1), 75-81. https://doi.org/10.1080/03079450701802206