Bone healing of the ulna after osteotomy and fixation with a maxillofacial miniplate (Compact 1.0) was studied in feral pigeons (Columba livia). The ulna and radius were transected with an oscillating bone saw to produce a diaphyseal fracture. Two different procedures for fixation were compared. In procedure 1 (n = 6), the ulna was stabilized with a 6-hole maxillofacial miniplate. In procedure 2 (n = 4), the ulna was stabilized with the plate, and the radius was stabilized with an intramedullary 1.0 Kirschner wire. Plate distortion and bending occurred in all 6 birds with fractures that were immobilized with the plate only, and 1 plate failure was noted with subsequent synostosis. When both bones were immobilized, 2 cases of minimal plate deformation and 1 case of cortical fragment displacement occurred. Callus formation was significantly less pronounced after procedure 2 as compared with procedure 1; however, primary bone healing was not achieved with either procedure. From these results we conclude that dorsal single plating of the ulna with a 6-hole maxillofacial miniplate in experimentally induced ulnar and radial fractures in pigeons does not result in adequate stabilization.

A juvenile Meyer's parrot (Poicephalus meyeri) was presented for acute depression and crop stasis and died. On histopathologic examination, intranuclear inclusion bodies were seen in the liver, spleen, proventriculus, and intestinal mucosa. DNA in situ hybridization of tissues was positive for adenovirus and negative for herpesvirus, polyomavirus, and circovirus. Degenerate (polymerase chain reaction [PCR]) primers targeting a conserved region of adenovirus DNA–dependent DNA polymerase were used to amplify and sequence a product from paraffin-embedded tissue. This is the first sequence information available for a psittacine adenovirus. Phylogenetic and comparative sequence analysis indicated that this virus is a member of the genus Aviadenovirus and is here termed Meyer's parrot adenovirus 1. Consensus nested PCR and sequencing can be used to rapidly identify novel adenoviruses, and DNA in situ hybridization may be used for rapid localization of novel viruses in tissues. Identification of adenoviral types and species will provide useful diagnostic, prognostic, and epidemiologic information for clinicians.

Peripheral quantitative computed tomography (pQCT), a noninvasive method for measuring bone characteristics, was used to evaluate bone healing in 3 white leghorn chickens (Gallus domesticus) after radial osteotomy at 22 days of age. The time sequence for callus formation and mineralization over a 45-day period was examined by performing serial cross-sectional scans of the osteotomized radius of each bird daily from day 2 to day 29 and on days 42 and 45 after surgery. Complete data were available for 2 birds. Formation of a new marrow cavity was apparent by 4 weeks after surgery, and union of the bone ends appeared complete by day 42. Bone mineral content (BMC), bone mineral density (BMD), and cross-sectional area (CSA) were measured at the radial osteotomy site, at 3 mm proximal to it, and at the corresponding areas on the ulna. The radial osteotomy site began to mineralize by day 4, and BMC and CSA increased approximately 100% in both birds between days 5 and 10. In bird 2, BMC and CSA continued to increase (55% and 74%, respectively). Peak radial levels of both BMC and CSA were followed by plateaus lasting approximately 7 days, then both levels decreased during callus resorption. The radial BMD increased during these plateaus, then decreased as the callus was remodeled. Between days 29 and 42, the BMD of the radial osteotomy site increased and approached that of the corresponding ulna. The sequences of changes in BMC, CSA, and BMD after day 10 were similar in each bird. These results indicate that pQCT is a useful tool to monitor postosteomy bone healing in chicks.

In psittacine birds, the diagnosis of sarcocystosis is usually made on postmortem examination, and antemortem testing has been limited to muscle biopsy. We studied the applications of a serologic assay for antibody and plasma protein electrophoresis for changes in protein fractions in the antemortem diagnosis of sarcocystosis in psittacine birds. Several confirmed cases of sarcocystosis in psittacine birds were examined. To detect antibody, an indirect immunofluorescent assay was employed using Sarcocystis falcatula merozoites. Plasma samples from birds that demonstrated chronic neurologic signs had reactivity to the S falcatula antigen, and increases were found in the beta and gamma fractions by plasma protein electrophoresis. Conversely, in birds with the classic peracute onset of dyspnea and subsequent death, test results by either methodology were negative. These findings support the use of these 2 diagnostic tools as aids in the antemortem diagnosis of the nonperacute form of sarcocystosis in psittacine birds.

The disposition and effects of 2 formulations of injectable doxycycline administered at 100 mg/kg were investigated to determine if plasma concentrations considered adequate for treating avian chlamydiosis (1 μg/ml) could be safely maintained in 3 species of psittacine birds. Five orange-winged Amazon parrots (Amazona amazonica) that received a commercial doxycycline hyclate formulation (20 mg/ml) intramuscularly achieved maximum plasma doxycycline concentrations of 9.33 ± 0.82 μg/ml and maintained concentrations >1 μg/ml for 5 days. In a second trial, 8 orange-winged Amazon parrots and 8 Goffin's cockatoos (Cacatua goffini) received micronized pharmacist-compounded doxycycline (75 mg/ml IM). In orange-winged Amazon parrots, maximum plasma doxycycline concentration was 2.54 ± 0.38 μg/ml, and concentrations of approximately 0.5 μg/ml were sustained from 24–168 hours. In Goffin's cockatoos, maximum plasma doxycycline concentration was 3.49 ± 0.18 μg/ml, and concentrations >1 μg/ml were maintained for at least 168 hours. In a third trial, groups (n = 4) of orange-winged Amazon parrots, Goffin's cockatoos, and timneh African grey parrots (Psittacus erithacus timneh) received micronized pharmacist-compounded doxycycline (100 mg/ml IM); a separate group of timneh African grey parrots (n = 4) received the same dose subcutaneously. Plasma doxycycline concentrations were lower than in the second trial, and no group achieved 1 μg/ml. After 24 hours, concentrations were sustained at approximately 0.4–0.8 μg/ml in Goffin's cockatoos and at 0.3–0.4 μg/ml in orange-winged Amazon parrots and timneh African grey parrots for at least 20 days. No significant difference was found in doxycycline plasma concentrations in timneh African grey parrots injected subcutaneously as compared with those in parrots injected intramuscularly. Reaction at the injection site was observed in all birds receiving pharmacist-compounded doxycycline, including marked, persistent swelling at the intramuscular injection site and sloughing of skin and scab formation at subcutaneous injection sites. The results of this study show that both the efficacy and the severity of injection-site reactions seen with use of this particular formulation of pharmacist-compounded doxycycline may vary depending on the species treated and particular drug batch.

Information about physiologic concentrations of vitamins A and E in captive psittacine birds would be useful in the diagnosis of potential vitamin deficiencies or toxicoses. To help provide this information, a retrospective study was done to assess circulating concentrations of vitamins A and E in captive Psittaciformes at 6 facilities representing 12 genera and 33 species. Plasma or serum samples collected from psittacine birds were analyzed for concentrations of α-tocopherol (n = 115) and retinol (n = 167). Mean retinol concentration (± standard deviation) in all birds was 0.471 ± 0.209 μg/ml, and mean α-tocopherol concentration was 13.05 ± 6.60 μg/ml. When compared by subfamily and genera, concentrations of both retinol and α-tocopherol differed significantly among groups. Post hoc testing demonstrated that differences in concentrations of retinol and, at the subfamily level, of α-tocopherol were attributable to low concentrations in Pesquet parrots (Psittrichas fulgidus). Differences at the genus level were mainly caused by high α-tocopherol concentrations in hyacinth macaws (Andorhynchus hyacinthinus). These results demonstrate that circulating concentrations of vitamins A and E in psittacine birds depend significantly on subfamily and genera.

Knemidocoptes mutans, commonly known as the scaly-leg mite, causes disease in various avian species. In a peep of bantam chickens, proliferative skin lesions were observed on the shanks of 6 of 29 birds, with digit necrosis observed in some birds. Histologic examination of the necrotic digits revealed Knemidocoptes species in the stratum corneum. No new cases of scaly-leg mite infection occurred in the flock after administration of ivermectin, and treatment halted the progression of the disease process in infected chickens. This case report documents that severe Knemidocoptes infection can be associated with digit necrosis in chickens.

A 20-year-old male cockatiel (Nymphicus hollandicus) exhibiting dysphagia, regurgitation, and lethargy was diagnosed with invasive squamous cell carcinoma involving the crop. The neoplastic mass was closely associated with the right vagal nerve and was obstructing 80% of the crop lumen. Dysphagia appeared to be linked to nerve dysfunction resulting in ileus of the upper digestive tract. This is the first published report of squamous cell carcinoma in the crop of a psittacine species resulting in nerve dysfunction and possible vagal indigestion.