Blood parasites of imported psittacine birds.

Of 117 imported psittacine birds examined for the presence of blood parasites, 18 (15-3 per cent) were found to be infected. The most common parasites were microfilaria and Haemoproteus, but Aegyptianella and a Trypanosoma sp were also observed. Haemoproteus handai was diagnosed in several birds and for the first time in lesser sulphur-crested cockatoos. The significance of the parasites observed is discussed and also that of other haematozoa recorded from psittacines but not found during the present survey.     

Feather picking and self-mutilation in psittacine birds.

Feather-picking and self-mutilation behaviors are common in psittacine birds. These behaviors are best defined as stereotypic behaviors or obsessive compulsive disorders. There is likely a genetic predisposition for these behaviors as reflected in the overrepresentation of a number of species of psittacines. Stereotypies most often result from a high level of arousal and the inability to respond with the appropriate natural behaviors. More specifically, conflict may be induced by the absence of releasing stimuli or target objects. On a chemical level, stereotypic behavior appears to be related to an increased dopaminergic activity and an increased dopamine turnover. Feather-picking and self-mutilation patients are challenging to treat and are most likely to respond to treatment at an early stage of development. The best results are obtained by identifying and removing the cause of conflict, enhancing the environment, using appropriate drugs when indicated, and employing counter-conditioning.     

Pacheco's disease in psittacine birds

Pacheco's disease, caused by a herpesvirus, was diagnosed in 20 groups of 47 psittacine birds received for necropsy. A tentative diagnosis, based on history and gross lesions, was confirmed by one or more of the following observations: Cowdry type A inclusions in the hepatocytes and cells of other affected tissues, pathogenicity of tissue suspensions for chicken embryos, cytopathic effects of herpesvirus in monolayers of chicken embryo fibroblasts, and demonstration of herpesvirus in cell-culture fluid by electron microscopy.     

Wound healing and management in psittacine birds.

Psittacines and other companion avian species often develop wounds requiring some form of medical or surgical therapy. Advancing technology in the field of wound care and management continues to evolve for use by the veterinary clinician. Although not all wounds can be successfully treated, many can be reduced and minimized with therapy. Consideration of the overall health, management, and nutrition of the avian patient will also aid in wound management. The avian patient with normal immune function and optimal nutrition will have improved wound healing compared with an immunocompromized or malnourished patient. The duration of treatment and potential stress of the wound-management program should also be taken into consideration when selecting a treatment program for the avian patient.     

Bacterial septicemias in two psittacine birds

Pasteurellosis was diagnosed in a red-fronted conure (Aratinga wagleri) that had been bitten on its breast by a cat 2 weeks before death. The wound spread rapidly, involving the skin over the entire breast and the underlying musculature. Septicemia that followed dermatitis and myositis was the cause of death. Pasteurella multocida was isolated in pure culture from the heart blood and liver. Diagnosis of Escherichia coli septicemia and enteritis in a hyacinth macaw (Anodorhynchus hyacinthinus) was based on lesions such as generalized hyperemia and hemorrhages in visceral organs, fibrinonecrotic lesions in the intestine, and isolation of E coli in pure culture from the heart blood, liver, and intestine.     

Proventricular dilatation syndrome in large psittacine birds

Proventricular dilatation was diagnosed in 16 psittacine birds. Signs included anorexia, lethargy, weight loss, and intermittent vomiting. The proventriculus in all birds was thin-walled and impacted with ingesta and occupied most of the body cavity. Microscopic changes in the proventriculus varied from none to an infiltration of lymphocytes, macrophages, and heterophils. There was no evidence of viral or bacterial infection or lead toxicity.     

Distribution of Malassezia organisms on the skin of unaffected psittacine birds and psittacine birds with feather-destructive behavior

OBJECTIVE: To ascertain whether Malassezia organisms can be detected via cytologic examination and fungal culture of samples from the skin surface of psittacine birds and determine whether the number of those organisms differs between unaffected psittacines and those that have chronic feather-destructive behavior or differs by body region. DESIGN: Prospective study. ANIMALS: 50 unaffected psittacines and 53 psittacines that had feather-destructive behavior. PROCEDURE: Samples were collected by use of acetate tape strips from the skin of the head, neck, proventer, propatagium, inguinal region, and preen gland area of each bird; 0.5-cm(2) sample areas were examined microscopically for yeast, and samples were also incubated on Sabouraud dextrose agar. Polymerase chain reaction assays specific for Malassezia spp, saprophytic fungi, and Candida albicans were performed on DNA prepared from cultured colonies; nested PCR evaluation for Malassezia pachydermatis was then performed. RESULTS: Microscopically, 63 of 618 (10%) tape-strip samples contained yeast. Thirty cultured colonies were assessed via PCR assays, and all yielded negative results for Malassezia spp; C albicans was identified in 2 colony samples. The numbers of yeast identified microscopically in psittacines with feather-destructive behavior and in unaffected birds did not differ significantly, and numbers did not differ by body region. CONCLUSIONS AND CLINICAL RELEVANCE: Yeast were identified infrequently via cytologic examination of samples from the skin surface of unaffected psittacine birds or those that had chronic feather-destructive behavior. If yeast are identified on the skin of birds with feather-destructive behaviors, fungal culture of skin samples should be performed to identify the organism.     

Radiographic determination of proventricular diameter in psittacine birds

OBJECTIVE: To establish an objective method of determining proventricular diameter in psittacine birds by assessment of lateral whole-body radiographic views. DESIGN: Retrospective case-control study. ANIMALS: 100 parrots with no signs of gastric disease and 19 parrots with signs of gastric disease. PROCEDURES: Measurements were obtained for the following variables: proventricular diameter at the level of the junction between the last thoracic vertebra and synsacrum, maximum distance between the dorsal serosa of the proximal aspect of the proventriculus and dorsal border of the sternum, maximum coelomic cavity height at the level of the proximal aspect of the proventriculus, and maximum dorsoventral height of the keel of the sternum. The ratio of proventricular diameter to each of those measurements was calculated and compared among species within the group without signs of gastric disease and between the gastric and nongastric disease groups. RESULTS: No significant differences were seen among species of parrots without signs of gastric disease for any ratio, but there were significant differences between parrots with gastric signs and those without gastric signs for all ratios. Only the proventricular diameterto-maximum dorsoventral height of the keel of the sternum ratio had no numeric overlap between groups. Sensitivity and specificity of the ratio for detection of proventricular enlargement were both 100%. Six causes associated with proventricular enlargement were identified. CONCLUSIONS AND CLINICAL RELEVANCE: Evaluation of the proventricular diameter-to-keel height ratio is a new method for evaluating proventricular size in psittacines. Ratio values < 0.48 indicate normal proventricular diameter and the absence of proventricular disease.