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Objective

To characterize prevalence and type of cardiac disease evident in psittacine birds during postmortem examination.

Design

Retrospective study.

Animals

26 psittacine birds with gross and histologic evidence of cardiac disease.

Procedure

Records of postmortem examinations of psittacine birds necropsied during a 4-year period were reviewed. Data on gross and histologic evidence of cardiac disease were analyzed. Birds identified included those in which congestive heart failure (CHF) was considered the primary cause of death and those in which substantial cardiac disease was evident, despite a lack of postmortem findings supportive of CHF.

Results

Of 269 psittacine birds necropsied, 26 (9.7%) had evidence of cardiac disease. In 15 (58%) birds with cardiac disease, changes consistent with CHF were evident and were sufficiently severe as to be considered the cause of death. The remaining 11 birds had cardiac lesions secondary to other systemic diseases; cardiac lesions were considered to be an incidental finding in these birds, and CHF was not evident. Of the 15 birds with CHF, 10 had evidence of right ventricular or biventricular failure, whereas only 5 had evidence of left ventricular failure.

Clinical Implications

Prevalence of cardiac disease in the psittacine birds reported here was similar to that seen clinically in other companion animals. The high incidence of right ventricular or biventricular heart failure in psittacine birds was similar to that for poultry in which lesions of right-sided heart failure predominate. (J Am Vet Med Assoc 1998;212:1737–1742)

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

Adult umbrella cockatoos, Moluccan cockatoos, African grey parrots, and a yellow-headed Amazon parrot were inoculated im or sc with β-propiolactone-treated psittacine beak and feather disease (pbfd) virus. Thirty- to 45-day-old African grey parrot, umbrella cockatoo, and sulphur-crested cockatoo chicks also were vaccinated with the same inoculum. The hemagglutination inhibition (hi) and agar-gel diffusion tests were used to assay for post-vaccination development of anti-pbfd virus antibodies. All adult vaccinates seroconverted and had increases in hi and precipitating antibodies. The vaccinated chicks had increased concentrations of hi antibodies, but precipitating antibodies could not be detected. To demonstrate that chicks from vaccinated hens are protected from pbfd virus challenge, 3 African grey parrot chicks and 2 umbrella cockatoo chicks from vaccinated hens and 1 African grey parrot chick and 1 umbrella cockatoo chick from nonvaccinated hens were exposed to purified pbfd virus. Chicks from the vaccinated hens remained clinically normal during the 50-day test period. Chicks from the nonvaccinated hens developed clinical and histologic lesions of pbfd. Infected tissues from these birds were confirmed to contain viral antigen, using immunohistochemical staining techniques. The pbfd virus was recovered from the affected birds. These findings indicate that adult and 30- to 45-day-old psittacine birds will seroconvert following vaccination with β-propiolactone-treated pbfd virus. Also, hens inoculated with β-propiolactone-treated pbfd virus produce chicks that are, at least temporarily, resistant to virus challenge.

Free access
in American Journal of Veterinary Research
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Summary

Each week over a 6-week period, 80 adult cockatiels (Nymphicus hollandicus) of either gender were dosed orally with fine particles of pure zinc or galvanized coating removed from welded wire mesh. At dosage of 32 mg/wk, all birds became severely ill and either died or were euthanatized within 2 weeks. Dosage of 2 mg/wk induced chronic illness marked by dullness, weight loss, and intermittent excretion of greenish droppings. Necropsy findings were unremarkable, except for signs suggestive of impaired gastrointestinal tract motility and histologic degenerative changes associated with focal mononuclear infiltration in the liver, kidneys, and pancreas. Tissue, especially pancreatic, contents of zinc were markedly high. Pure zinc was as toxic as galvanizing zinc. White rust, an oxidation product, also was toxic. The galvanized coating on cages and flights must be carefully wire-brushed and examined before housing psittacine birds.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate flow cytometric analysis for sex identification in 3 psittacine species, establish reference values for blood cell DNA content for each species, and determine effects of sample storage on DNA content.

Animals—36 orange-winged Amazon parrots, 41 budgerigars, and 39 cockatiels.

Procedure—Blood samples were stained and analyzed by use of flow cytometry to measure cellular DNA content. Samples were analyzed immediately after collection and after being stored at 4 C for 48 and 72 hours.

Results—Mean DNA content (picograms per cell) was 3.248 for Amazon parrots, 2.702 for budgerigars, and 2.946 for cockatiels; DNA concentrations in samples analyzed immediately overlapped in a male and a female Amazon parrot and among 19 cockatiels. For budgerigars, DNA overlap between sexes was not detected in samples analyzed immediately or after storage for 72 hours. Sex was identified correctly in 94.4% of Amazon parrots, 100% of budgerigars, and 51.3% of cockatiels. For both sexes, DNA content in samples analyzed immediately was significantly different from that of stored samples.

Conclusions and Clinical Relevance—Flow cytometric analysis was accurate for sex identification of Amazon parrots and budgerigars. Sample storage at 4 C for 48 or 72 hours caused variability in DNA content. (Am J Vet Res 2000;61:847–850)

Full access
in American Journal of Veterinary Research

SUMMARY

Psittacine beak and feather disease (pbfd) virus was recovered from the feces and crop washings from various species of psittacine birds diagnosed with pbfd. High concentrations of the virus also could be demonstrated in feather dust collection from a room where 22 birds with active cases of pbfd were being housed. The virions recovered from the feces, crop, and feather dust were confirmed to be pbfd virus by ultrastructural, physical, or antigenic characteristics. Virus recovered from the feather dust and feces hemagglutinated cockatoo erythrocytes. The specificity of the agglutination was confirmed by hemagglutination inhibition, using rabbit antibodies against pbfd virus. During the test period, 26% (8 of 31) of the birds screened were found to be excreting pbfd virus in their feces, and 21% (3 of 14) of crop washings were positive for pbfd virus. Some birds in the sample group had active cases of diarrhea, whereas others had normal-appearing feces. Diarrhea was found to be the only significant indicator of whether a bird was likely to be excreting virus from the digestive tract. These findings suggest that exposure of susceptible birds to pbfd virus may occur from contact with contaminated feather dust, feces, or crop secretions. Viral particles that were morphologically similar to parvovirus (20- to 24 nm-icosahedral nonenveloped virions) also were recovered from feces of some of the birds.

Free access
in American Journal of Veterinary Research

SUMMARY

Conditions for psittacine beak and feather disease (pbfd) virus hemagglutination and hemagglutination-inhibition (hi) test reactions are defined. The pbfd virus was found to hemagglutinate cockatoo and some guinea pig erythrocytes. The hi test was used to assay serum antibody titer in birds with active pbfd virus infections and in others that had been exposed to diseased birds. On the basis of hi antibody titers in psittacine birds that had been exposed to pbfd virus, but remained clinically normal, we suggest that some birds exposed to the virus are able to mount an effective immune response. Birds with active pbfd virus infections had lower antibody values than did birds that had been exposed to the virus, but remained clinically normal. On the basis of these findings, the ability to develop a suitable hi antibody response may be crucial in determining the disease status of susceptible birds exposed to the pbfd virus. If hi antibodies are found to have neutralizing activity, then the fact that a high hi titer was induced in birds inoculated with purified pbfd virus might suggest that an immunization program would be effective in preventing pbfd virus infections.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To validate a novel high-sensitivity radioimmunoassay (RIA) procedure developed to accurately measure the relatively low serum total thyroxine (T4) concentrations of birds and reptiles and to establish initial reference ranges for T4 concentration in selected species of psittacine birds and snakes.

Animals—56 healthy nonmolting adult psittacine birds representing 6 species and 42 captive snakes representing 4 species.

Procedure—A solid-phase RIA designed to measure free T4 concentrations in dialysates of human serum samples was used without dialysis to evaluate total T4 concentration in treated samples obtained from birds and reptiles. Serum T4 binding components were removed to allow assay of undialyzed samples. Assay validation was assessed by determining recovery of expected amounts of T4 in treated samples that were serially diluted or to which T4 was added. Intra- and interassay coefficient of variation (CV) was determined.

Results—Mean recovery of T4 added at 4 concentrations ranged from 84.9 to 115.0% and 95.8 to 119.4% in snakes and birds, respectively. Intra- and interassay CV was 3.8 and 11.3%, respectively. Serum total T4 concentrations for 5 species of birds ranged from 2.02 to 7.68 nmol/L but ranged from 3.17 to 142 nmol/L for blue-fronted Amazon parrots; concentrations ranged from 0.21 to 6.06 nmol/L for the 4 species of snakes.

Conclusions and Clinical Relevance—This new RIA method provides a commercially available, accurate, and sensitive method for measurement of the relatively low serum T4 concentrations of birds and snakes. Initial ranges for the species evaluated were established. (Am J Vet Res 2001;62:1750–1767)

Full access
in American Journal of Veterinary Research

SUMMARY

Objective

To determine safety, immunogenicity, and efficacy of an inactivated avian polyomavirus vaccine in nonbudgerigar psittacine birds that varied in age, species, and immunologic status.

Animals

Safety of the vaccine was evaluated in 1,823 psittacines representing more than 80 species. Immunogenicity was evaluated in 285 birds (260 of various Psittaciformes species, 25 chickens). Efficacy was evaluated in 104 birds (78 of various Psittaciformes species, 26 chickens).

Procedures

Safety was evaluated by vaccinating birds that were determined to be seronegative or seropositive (titer > 1:10) prior to vaccination. Birds were then evaluated for clinically detectable systemic or local reactions for 2 months to 2 years. Immunogenicity was evaluated by testing for virus-neutralizing antibodies, vaccinating each bird twice, and then testing for a significant change in antibody titer. Efficacy was evaluated by vaccinating birds, followed in 2 to 4 weeks by intramuscular or intravenous challenge exposure. After challenge exposure, protection was evaluated by attempting to recover virus from tissues or by observing birds for clinical signs of disease and testing for a significant change in titer.

Conclusions

Avian polyomavirus vaccine is safe, immunogenic, and efficacious for use in multiple species of mature and immature psittacines.

Clinical Relevance

Until now, prevention of polyomavirus infection in psittacine birds could only be accomplished through strict isolation to reduce potential exposure to the virus. The USDA-registered inactivated avian polyomavirus vaccine can safely be used to protect vaccinates from infection and control spread of this virus in flocks. (Am J Vet Res 1998,59:143–148)

Free access
in American Journal of Veterinary Research