Wounds as the Portal of Entrance for Parrot Bornavirus 4 (PaBV-4) and Retrograde Axonal Transport in Experimentally Infected Cockatiels (Nymphicus hollandicus).

In this study, we investigated the natural route of infection of psittacine bornavirus (PaBV), which is the causative agent of proventricular dilatation disease (PDD) in psittacines. We inoculated two infection groups through wounds with a PaBV-4 isolate. In nine cockatiels (Nymphicus hollandicus) we applied a virus suspension with a titer of 103 50% tissue culture infection dose (TCID50) via palatal lesions (Group P, P1-9). In a second group of three cockatiels, we applied a virus suspension with a titer of 104 TCID50 to footpad lesions (Group F, F1-3). In two cockatiels, the control (or "mock") group, we applied a virus-free cell suspension (Group M, M1-2) via palatal lesions. The observation period was 6 mo (Groups P and M) or 7 mo (Group F). We monitored PaBV-4 RNA shedding and seroconversion. At the end of the study, we examined the birds for the presence of inflammatory lesions, PaBV-4 RNA, and antigen in tissues, as well as virus reisolation of brain and crop material. We did not observe any clinical signs typical of PDD during this study. We also did not see seroconversion or PaBV RNA shedding in any bird during the entire investigation period, and virus reisolation was not successful. We only found PaBV-4 RNA in sciatic nerves, footpad tissue, skin, and in one sample from the intestine of Group F. In this group, the histopathology revealed mononuclear infiltrations mainly in skin and footpad tissue; immunohistochemistry showed positive reactions in spinal ganglia and in the spinal cord, and slightly in skin, footpad tissues, and sciatic nerves. In Groups P and M we found no viral antigen or specific inflammations. In summary, only the virus application on the footpad lesion led to detectable PaBV RNA, mononuclear infiltrations, and positive immunohistochemical reactions in tissues of the experimental birds. This could suggest that PaBV spreads via nervous tissue, with skin wounds as the primary entry route.

Horner Syndrome With Ipsilateral Wing Paresis in a Wild, Juvenile Yellow-Tailed Black Cockatoo (Calyptorhynchus funereus).

A juvenile yellow-tailed black cockatoo (Calyptorhynchus funereus) was presented with paresis of the right wing, ptosis, and miosis of the right eye; feather erection of the right side of the head and neck; and a penetrating injury over the right pectoral muscle. Temporary reversal of ptosis, miosis, and feather erection after administration of phenylephrine drops confirmed a diagnosis of Horner syndrome. Computed tomographic imaging revealed a fractured rib, traumatic lung lesions, and subcutaneous emphysema. The right-sided Horner syndrome and wing paresis were attributed to a sympathetic nerve trauma of the eye and feathers and to the brachial plexus, respectively. This report describes the diagnosis and resolution of ptosis and miosis within 8 weeks and recovery of feather symmetry and wing function within 11 weeks of the cockatoo's initial presentation with a conservative-management treatment plan.

Rectricectomy With Pygostylectomy for Resolution of Feather Trauma in an Umbrella Cockatoo (Cacatua alba).

Feather trauma is a common problem among pet birds, especially those with trimmed wing feathers, and often affects remiges and rectrices. Damage can become chronic if new feathers remain unprotected by fully formed adjacent feathers. The follicles can become damaged and poorly functional over time. A 6-month-old male umbrella cockatoo (Cacatua alba) was presented for examination because of feather damage that occurred shortly after receiving a wing trim by the owner. Over the next 18 months, various medical, behavioral, and husbandry methods failed to allow normal regrowth of the tail feathers. The bird presented 25 times over the 18-month period for problems associated with broken blood feathers in the tail. Feather imping was ruled out because of the lack of hollow adult shafts to serve as a base. Diagnostic tests included hematologic testing and biochemical analysis, circovirus testing, feather biopsy, and radiographs, results of which were unremarkable. Because of the chronic pain associated with the frequent rectrix damage, a complete rectricectomy was performed. All of the rectrical follicles as well as the pygostyle were surgically removed. Healing was uneventful and the bird has been clinically normal with no further blood feather injury for 24 months after surgery.

Multiple Infiltrative Intraosseous Lipomas in the Appendicular Skeleton of a Rose-breasted Cockatoo (Eolophus roseicapilla) with a Humeral Fracture.

A 9-year-old female rose-breasted cockatoo (Eolophus roseicapilla) was presented for a humeral fracture. At presentation, the bird was severely lethargic and obese. On physical examination, an open right humeral fracture, healed left ulnar fracture, and intertarsal joint swelling were present. Results of hematologic testing and biochemical analysis revealed severe leukocytosis with heterophilia and increased creatine kinase and aspartate aminotransferase activities consistent with musculoskeletal lesions. Radiographs confirmed a right humeral fracture and showed severe polyostotic lytic and expansile lesions of the appendicular skeleton, as well as an enlarged hepatic silhouette. Surgical repair of the fracture was attempted, but the bird died during the procedure. Postmortem examination revealed severe bone deformities involving the fractured humerus, both ulnas, and the left tibiotarsus. Histologic findings were consistent with multiple intraosseous lipomas of the long bones and severe hepatic lipidosis. To our knowledge, this is the first report of multiple intraosseous lipomas in a bird.

Presentation and prognostic indicators for free-living black cockatoos (Calyptorhynchus spp.) admitted to an Australian zoo veterinary hospital over 10 years.

The veterinary records of three species of free-living, endangered black cockatoos (Calyptorhynchus spp.; n = 565) admitted to the Perth Zoo Veterinary Hospital in Western Australia during a 10-yr period (2000-09) were analyzed to determine the effect of clinical presentation and treatment on survival to release. The most-common reason for admission was trauma (at least 76.7% of cases), and trauma was also the most-frequent finding on necropsy examination (80.1% of cases). Anemia and paralysis-paresis were significant factors determining the decreased likelihood of survival of cockatoos undergoing rehabilitation. Human activities, in particular vehicle strike, were significant causes of morbidity and mortality in free-living black cockatoo populations.

Unilateral evisceration of an eye following cornea and lens perforation in a sulfur-crested cockatoo (Cacatua galerita).

A 24-year old male sulfur-crested Cockatoo (Cacatua galerita) was presented with a subacute perforation of the cornea without involvement of the lens. The bird was treated conservatively and the eye remained quiescent up to a second traumatic corneal perforation associated with a lens capsule rupture 15 months later. Due to the second perforating trauma of an already blind eye involving the lens, evisceration of the eye was performed. Two months after surgery the cosmetic result was excellent. Treatment options for perforating ocular traumas in captive birds are discussed in detail.