Mycobacteriosis has long been recognized as a disease of companion psittacine birds. In this review, the signalment, clinical signs of disease, and diagnosis of mycobacteriosis in psittacine birds are presented. Although treatment of birds with mycobacteriosis is controversial, therapeutic protocols for use in psittacine birds have been developed based on protocols used in humans. Results of recent studies indicate that mycobacteriosis in psittacine birds is unlikely to represent a significant health risk for humans. However, the potential for zoonotic disease must be considered, especially if persons who are immunocompromised are in contact with an infected bird.

A 4.5-kg, adult bald eagle (Haliaeetus leucocephalus) was presented after being found unable to fly. Crepitus was palpated in the left shoulder; however, the wing position was normal. Radiographs revealed caudoventral luxation of the left coracoid, affecting its distal articulation with the clavicle and its proximal articulation with the sternum. The luxation affecting the coracoid-sternum articulation was repaired by using a 4-hole, 1.5-mm T-plate and a 6-hole, 2.0-mm dynamic compression plate (DCP) placed side by side. The luxation affecting the coracoid and the clavicle was repaired by 2 cerclage wires in a simple interrupted pattern. Before a scheduled release, the bird sustained a closed, complete mid diaphyseal transverse fracture of the right tibiotarsus, which most likely occurred during recapture from the flight cage. The fracture was surgically repaired with 2 circumferential cerclage wires, an intramedullary Kirschner wire and one 10-hole, 2.7-mm DCP. The bird was successfully released, 105 days after the first surgery, near the location where it was found.

Three bald eagles (Haliaeetus leucocephalus) found along highways and unable to fly were presented for evaluation. All eagles exhibited sternal recumbency, as well as flaccid hind limb and tail paralysis. Vertebral column and spinal cord trauma were suspected as the cause. One bird died, whereas the remaining 2 birds were stabilized for diagnostic imaging studies. All 3 birds were evaluated by radiography and magnetic resonance imaging (MRI) for diagnosis and for prognosis in the live birds. Radiographic findings in all 3 birds were inconclusive, whereas MRI results showed extensive damage of the spinal cord and vertebral column, precluding functional recovery. The 2 surviving birds were euthanatized. In all birds, MRI assessments correlated well with necropsy and histopathologic findings.

A mature bald eagle (Haliaeetus leucocephalus) was diagnosed with mycobacterial infection after being presented for an inability to fly, emaciation, and a swelling of the left tibiotarsal-tarso metatarsal joint. Results of a complete blood cell count revealed a persistent, marked leukocytosis, with heterophilia, monocytosis, and anemia. Radiographs revealed lysis of the left distal tibiotarsus and soft-tissue swelling around the left tibiotarsal-tarsometatarsal joint, multiple pulmonary opacities, and an enlarged liver. Endoscopic evaluation and biopsy of caseated material within the left caudal coelom revealed acid-fast organisms. The eagle was euthanatized, and results of necropsy and histologic evaluation revealed caseated granulomas of the intestine, lungs, air sacs, and subcutaneous regions of the hock. Results of culture, a polymerase chain reaction testing, and direct deoxyribonucleic acid (DNA) sequencing for mycobacterial 16S ribosomal ribonucleic acid DNA determined this organism most likely to be Mycobacterium avium.

A disease condition with clinical and pathologic findings compatible with psittacine proventricular dilatation disease was diagnosed in a canary (Serinus canaria), a greenfinch (Carduelis chloris), a long-wattled umbrellabird (Cephalopterus penduliger), and a bearded barbet (Lybius dubius). The canary and the greenfinch were kept as pets by different owners, whereas the bearded barbet and the long-wattled umbrellabird were kept in separate mixed species enclosures at the Barcelona Zoo. Clinical signs were variable in all 4 birds and included polyphagia, weight loss, weakness, and ataxia. Postmortem examination findings were also variable and included emaciation, hepatic and renal atrophy or enlargement, gallbladder dilatation, and intestinal and ventricular dilatation. Histopathologic lesions in all birds consisted of multifocal lymphoplasmacytic infiltration of myenteric and cardiac nerves and ganglia. These lesions are characteristic of proventricular dilatation disease of psittacine birds.

A 35-year-old yellow-naped Amazon parrot (Amazona ochrocephala auropalliata) was presented for gradually increasing inappetence, ataxia, weakness, and lethargy. Radiographic and ultrasonographic findings were strongly suggestive of atherosclerosis. Isoxsuprine, a peripheral vasodilator demonstrated to be of benefit in humans with intermittent limb pain, weakness, and lameness secondary to occlusive vascular disease, was selected for treatment. The bird's clinical signs resolved during treatment but recurred after varying periods of time when the medication was stopped intermittently. Nearly 3 years after the initial examination, the parrot was doing well on isoxsuprine therapy, with normal prehension of food with its feet and no recurrence of clinical signs.

An adult female Moluccan cockatoo (Cacatua moluccensis) was evaluated for a 10-day history of progressive ataxia and weakness. The bird had been exposed intermittently over a 3-day period to a cage that had previously housed juvenile raccoons. Results of diagnostic tests were inconclusive and, despite supportive care, the bird died 7 days after the initial presentation. Histopathologic examination revealed a single nematode larva in the midbrain that was consistent with Baylisascaris species and multifocal granulomas in the left ventricle of the heart. The neurologic disease in this bird was attributed to encephalitis caused by neural larval migration of the raccoon roundworm, Baylisascaris procyonis.