Avian polyomavirus (APV) causes disease in young parrots. There are two forms of the disease based on affected species: budgerigar fledgling disease and non-budgerigar polyoma infection. Both are characterized by peracute to acute death of preweaned neonates. Clinical signs occur 7–10 days after exposure and include lethargy, crop stasis, and death within 24–48 hours. Surviving budgerigars >3 weeks old often exhibit feather dystrophy (French molt or feather dusters). Older nonbudgerigar psittacines may have subclinical disease or hemorrhages and coagulopathies. Adult birds typically are resistant to infection; they will seroconvert and shed the virus for up to 90 days, then clear the infection. Antemortem diagnosis is accomplished with DNA probes of cloacal swab and blood samples. Aviary control methods include not housing budgerigars or lovebirds with other species, strict hygiene, limiting traffic in the nursery, and strict quarantine and testing of new birds. A vaccination is available.
Bacterial diseases are common in pet birds and should be considered in the differential list of any sick bird. Inappropriate husbandry and nutrition are often contributing factors. Neonates and young birds are especially susceptible. GI and respiratory infections are most common and can lead to systemic disease. Normal bacterial flora of companion birds include Lactobacillus, Corynebacterium, nonhemolytic Streptococcus, Micrococcus spp, and Staphylococcus epidermidis.
Diagnosis is based on clinical signs and results of cytologic examination and culture of tissue or swab samples. A Gram stain is used to identify normal flora, yeast, and spore-forming bacteria. Culture is needed to identify specific organisms and their sensitivity to antimicrobials. Samples can be obtained from the respiratory, GI, urinary, and reproductive tracts. Sample sites for culture and cytology include the choanal slit, sinus, cloaca, wounds, conjunctiva, internal organs (via ultrasound-guided fine-needle aspirates, endoscopic examination, or surgery), and blood.
