Cloacal papillomas in psittacines

Papilloma-like masses affecting the cloaca of 19 Amazons, 16 macaws, 3 parrots, 1 conure, and 1 parakeet were examined. Papillomatous lesions were characterized by proliferation of the lining epithelium on thin fibrovascular stalks. Carcinoma in situ was diagnosed in the cloaca of a macaw in addition to the other 16 macaws with papillomas. Papillomavirus group-specific antigens were not detected in any of the 41 lesions, using the peroxidase-antiperoxidase technique. The DNA extracts from 6 different frozen papillomas did not contain papillomavirus genomes detectable by Southern blot hybridization, using an African gray parrot cutaneous papillomavirus as a probe. Evidence of an infective agent was not found by electron microscopic examination of 8 of the papillomas. Inoculations of partially purified homogenates of a cloacal papilloma from a yellow-crowned Amazon did not induce lesion formation on cloacal mucosa of an adult yellow-crowned Amazon, green and yellow macaw, sulphur-crested cockatoo, or mollucan cockatoo.     

Sevoflurane anesthesia in psittacines.

Duration of anesthesia onset (time to intubation) and recovery (time to extubation, sternal and standing) and quality of recovery were compared for sevoflurane and isoflurane in 10 adult psittacines. Both agents were initially administered at an equal volume percentage (2%) rather than at equal minimum alveolar concentrations (MACs), therefore the initial concentration was above the isoflurane MAC for dogs and birds (1.3%) but below the sevoflurane MAC for dogs (2.3%). The time to intubation was significantly longer with sevoflurane because of initially delivering the sevoflurane below suspected MAC for birds. Although recovery times (time to extubation, sternal, and standing) were not significantly different, birds recovering from sevoflurane were less ataxic. Sevoflurane is a suitable inhalant agent for use in these psittacines and merits further study.     

Common procedures in psittacines.

General techniques performed on psittacine birds are described in this article, including restraint, handling, and grooming. Procedures to collect diagnostic samples and to administer therapeutic agents are detailed, including fluid therapy and nutritional support.     

Measurement of the cardiac silhouette in psittacines

OBJECTIVE: To determine reference values for size of the radiographic cardiac silhouette in healthy adult medium-sized psittacines. DESIGN: Prospective case series. ANIMALS: 46 African grey parrots (Psittacus erythacus), 7 Senegal parrots (Poicephalus senegalis), and 6 orange-winged Amazon parrots (Amazona amazonica). PROCEDURE: Birds were anesthetized, and ventrodorsal radiographic projections were obtained. Maximum width of the cardiac silhouette, width of the thorax at the level of the maximum width of the cardiac silhouette, and width of the coracoid were measured on the radiographs. Sternum length was directly measured on individual birds. Results of physical examination, electrocardiography, and echocardiography were normal in all birds. RESULTS: Mean cardiac silhouette width-to-sternum length ratio was 38%, mean cardiac silhouette width-to-thorax width ratio was 55%, and mean cardiac silhouette width-to-coracoid width ratio was 600%. Width of the cardiac silhouette was strongly correlated with length of the sternum, width of the coracoid, and width of the thorax. No significant differences between species were detected. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in healthy adult medium-sized psittacines, the cardiac silhouette on a ventrodorsal radiographic projection should be 35 to 41 % of the length of the sternum, 51 to 61 % of the width of the thorax, and 545 to 672% of the width of the coracoid.     

Coxiella-like infection in psittacines and a toucan

Seven psittacine birds and a toucan (Ramphastos toco) were diagnosed as infected with Coxiella-like bacteria, based on polymerase chain reaction and bacterial 16S rRNA gene sequence obtained from each bird's liver tissue. Most of the birds exhibited lethargy and weakness for several days prior to death. Gross lesions included mild to moderate emaciation and severely enlarged and mottled pale livers and spleens. Microscopically, there was multifocal necrosis of hepatocytes with infiltration of a mixed population of inflammatory cells, including lymphocytes, heterophils, plasma cells, and macrophages randomly scattered throughout in most birds. In several birds within the macrophages there were vacuoles containing basophilic small cocco-bacilli organisms measuring about 0.5-1 microm. The spleens had increased numbers of mononuclear phagocytic system cells, some of which had vacuoles that contained similar organisms, as observed in the liver. There was inflammation in the epicardium and endocardium, interstitium of the lungs, kidney, adrenal and thyroid glands, lamina propria of the intestine, and in occasional birds in the brain, bursa of Fabricius, and bone marrow associated with similar organisms in the macrophages. Transmission electron microscopy of the liver and lungs in most birds and in the thyroid glands of one bird revealed pleomorphic round to elongated bacteria measuring about 0.45 microm in diameter and more than 1.0 microm in length. Most of these organisms contained a peripheral zone of loosely arranged electron dense material that was located immediately beneath a trilaminar membrane. Occasional organisms contained nucleoids. This is the first documentation of disease presumptively associated with Coxiella-like bacteria in birds.     

Ultrasonographic appearance of primary gastric neoplasia in 21 dogs

The ultrasonographic findings in 21 dogs with histologically confirmed primary gastric neoplasia were reviewed. Location, shape of the gastric lesion, evidence of gastric wall thickening, wall layers affected, presence of ulceration, evidence of extension through the gastric wall and lymphadenopathy were recorded. Twelve dogs with carcinoma shared many ultrasonographic features with six dogs that had lymphoma, the majority having sessile masses that appeared to involve all layers of the gastric wall; many also had evidence of ulceration and lymphadenopathy. Signs of extension of the lesion through the serosal surface of the stomach were identified ultrasonographically only in dogs with carcinoma. In contrast, three dogs with leiomyoma or leiomyosarcoma each had a focal mass affecting the gastric antrum, and lymphadenopathy was not identified ultrasonographically in these dogs. Even without any specific patient preparation, ultrasonography enables a morphological assessment of gastric neoplasms that may prompt a tentative diagnosis of gastric neoplasia and stimulate further investigation.     

Four cases of neoplasia in captive wild birds

Four cases of malignant neoplasia in captive wild birds are described: an adenocarcinoma of the adrenal gland in a Mountain duck (Tadorna tadornoides), a malignant melanoma in the thoracic cavity of a Combed duck (Sarkidiornis melanotos), a hepatocellular carcinoma with pulmonary metastasis in an Asian Purple Swamphen (Porphyrio porphyrio), and an undifferentiated carcinoma in the abdomen with metastasis to skeletal muscle in a White-Breasted Waterhen (Amaurornis phoenicurus). The tumors were diagnosed during a 1-year period and represented an incidence of neoplasia of 3.1%. These appear to be the first documented cases of a malignant adrenal gland tumor and a non-ocular melanoma in the order Anseriformes. The hepatocellular carcinoma failed to react with an immunoperoxidase stain for alphafetoprotein.     

Examination and preventive medicine protocols in psittacines.

Preventive medicine is the best insurance for effective avian health maintenance and infectious disease control. Psittacine birds should have a yearly physical examination including a thorough history. Additionally, these animals require adequate management and husbandry including a commercial bird food diet supplemented with fresh fruits and vegetables. A complete preventive medicine program should include diagnostic tests as deemed necessary by the avian veterinarian in addition to strict quarantine, vaccination, and disinfection. Necropsy and histopathology are also important components of an effective preventive medicine program.     

Evaluation of intravenous fluorescein in intradermal allergy testing in psittacines

This study was designed to improve the clinical feasibility of intradermal skin testing of psittacine birds using intravenous fluorescein stain. Twenty-five healthy, anaesthetized Hispaniolan Amazon parrots (Amazona ventralis) were injected intravenously with 10 mg kg-1 fluorescein-sodium 1% followed by intradermal injections of 0.02 mL phosphate-buffered saline, histamine phosphate (1:100,000 w/v) and codeine phosphate (1:100,000 w/v) at the sternal apteria. Wheal diameters of reaction sites were measured grossly and under illumination with a Wood's lamp after 5 and 10 min. Fluorescence-enhanced injection sites were scored between 0 and 2, with 0 equivalent to normal skin and 2 equivalent to a plucked feather follicle. The presence of a fluorescent halo around intradermal injections was also recorded. Under Wood's light illumination at 10 min, histamine and saline were evaluated as positive and negative controls, respectively, based on a positive test having a halo and a score of 2. Sensitivity and specificity were each 76% for halo, 84 and 42% for score and 64 and 77% for combination of score and halo, respectively. Further, mean histamine reactions were significantly larger than codeine phosphate and saline (8.8 +/- 0.4 mm; 7.2 +/- 0.3 mm; 5.9 +/- 0.6 mm); however, this finding was not consistent in individual birds. Wheal size, halo presence and score were affected by site location independent from the injected compound. Intravenous fluorescein improved the readability of avian skin tests; however, the compounds tested raised inconsistent reactions in wheal size, score or halo presence. The compound-independent site effect raises concern on the validity of avian skin testing and warrants investigation of other techniques such as in vitro allergy testing. Based on our findings, intradermal allergy testing in psittacines with or without fluorescein is unreliable and cannot be recommended for practical clinical use.     

Intestinal neoplasia: A review of 34 cases

The clinicopathological features of 34 horses with a histological diagnosis of intestinal neoplasia were reviewed; these included 17 horses with lymphoma, five with gastrointestinal stromal tumours (GISTs), four with adenocarcinomas, three with leiomyosarcomas, two with leiomyomas, two with squamous cell carcinomas (SCC) and one with adenocarcinoma/mesothelioma. The mean age at presentation was 19 years (range 3–36 years), and 81% of cases occurred in horses aged 15 years or older. Weight loss, acute or recurrent colic, inappetence, diarrhoea, depression and pyrexia were the most common presenting clinical signs. Hyperfibrinogenaemia, hypoalbuminaemia and leukocytosis were the most common clinical pathological findings. Transabdominal ultrasonography and exploratory laparotomy were the most useful diagnostic tests. Neoplasia was identified in all regions of the intestinal tract, with the jejunum being most frequently affected. The presence of mass lesions or thickened intestinal walls on transabdominal ultrasound, coupled with other clinical findings, were suggestive of intestinal neoplasia. Where possible, complete surgical resection offered the best prognosis, but generally the prognosis was poor to hopeless.     

Comparative efficiency and accuracy of surgical and cytogenetic sexing in psittacines

Otoscopic surgical sexing and chromosome analysis through lymphocyte culture were undertaken in 22 psittacine birds of eight species for the purpose of establishing their sex. Comparison of the techniques involved considering success rate, quality of determination, cost, efficiency, and risk. Surgical endoscopy appears to be preferable to chromosome analysis in all categories except risk.