BFDV

Beak and feather disease virus (BFDV) is a small, non-enveloped circular DNA virus in the family Circoviridae that causes Beak and Feather Disease (BFD) in many psittacine birds, including parrots and cockatiels. BFDV affects both captive and wild populations and is one of the most widely reported diseases of parrots worldwide.

Virology and biology: BFDV has a single-stranded circular genome of about 1.8 to 2.0 kilobases. It replicates in lymphoid tissues, leading to immunosuppression and impaired molt. The virus is shed in feces, saliva, feather dust, and crop secretions, and can persist in the environment for extended periods. Transmission occurs through direct contact and potentially vertically from parent to offspring.

Clinical signs: In juvenile birds, BFDV commonly causes progressive feather loss and deformities, abnormal plumage, and beak malformations that impair feeding and grooming. Affected birds may show reduced growth and secondary infections due to immunosuppression. In adults, signs can be milder but immunosuppression may still occur, increasing susceptibility to other illnesses.

Diagnosis and management: Diagnosis is usually based on molecular testing (PCR) of blood, oral swabs, or feather samples; histopathology can reveal lymphoid depletion and circovirus-associated inclusions. There is no widely approved cure or vaccine. Management focuses on quarantine of new birds, good hygiene, disinfection of enclosures, and supportive care. Vaccination has been explored experimentally but is not broadly available.

Impact and considerations: BFDV is a concern for both the pet trade and wild populations, contributing to morbidity and, in some cases, mortality. It is not known to infect humans. Prevention relies on biosecurity, screening new arrivals, and minimizing exposure to infected birds and contaminated environments.