Ultrasound evaluation of small intestinal thickness and a comparison to body weight in normal chickens (Gallus gallus domesticus).

BACKGROUND: Ultrasound in avian patients is useful for identifying abnormalities within the coelomic cavity. A correlation between sonographic evaluation of jejunal thickness and body weight has been reported in mammals, but not the chicken (Gallus gallus domesticus). The purpose of this study was to prospectively assess the normal values of jejunal thickness in the chicken and compare this to body weight. METHODS: Coelomic ultrasound was performed on 89 clinically normal chickens with no history or signs of gastrointestinal disease. Two populations of hens (commercial layers and backyard purebred and mixed-breed hens) were used. Breed and ultrasonographically measured jejunal wall thickness were recorded in all hens. Body weight was recorded in 45 of the hens (mixed-breed and purebred backyard chickens). RESULTS AND CONCLUSION: There was no statistically significant correlation between body weight and ultrasonographically measured jejunal wall thickness. The mean thickness of the jejunal wall in healthy chickens was 2.1 ± 0.08 mm. Further studies comparing jejunal thickness in chickens with and without signs of GI disease would be useful.

Gastric adenocarcinoma in a diamond python (Morelia spilota spilota).

CASE REPORT: A 5-year-old captive male diamond python (Morelia spilota spilota) was presented with a 1-month history of regurgitation and anorexia and discrete coelomic distention. Physical examination revealed a firm, immobile mass at approximately two-thirds of the snout-vent length from the front of the head. Ultrasound-guided fine needle aspirate biopsy of the mass in the region of the stomach showed necrosis with bacterial infiltration and possibly neoplastic changes. A gastroscopy was conducted, but showed grossly normal gastric mucosa, confirmed by biopsy. On exploratory coeliotomy, it was confirmed the mass involved most of the stomach wall and occluded the gastric lumen. The mass was completely excised and based on histopathology, a diagnosis of gastric adenocarcinoma was made. The snake was found dead 12 h postoperatively, but no specific cause of death was found on postmortem examination. CONCLUSION: Most cases of adenocarcinoma in snakes go undiagnosed. This case report illustrates that the architecture of gastric masses may lead to false-negative gastric biopsy results in snakes with neoplasia.

Adenoviral infection in a collection of juvenile inland bearded dragons (Pogona vitticeps).

CASE REPORT: Juvenile inland bearded dragons (Pogona vitticeps) from a breeding collection in south-east Queensland were presented at age 6-10 weeks with neurological signs, poor growth and occasional deaths. Histopathological examination revealed that six of eight lizards had multifocal non-suppurative hepatitis associated with 5-10 µm diameter, smudgy, basophilic, hyaline intranuclear inclusion bodies that marginated the nuclear chromatin. These histological lesions were considered consistent with adenoviral hepatitis. Infection with adenovirus was confirmed positive in one of the eight dragons by PCR for adenoviral DNA. DNA was extracted from formalin-fixed paraffin-embedded pooled tissues of the juvenile inland bearded dragons and tested using a nested-PCR protocol with primers specific for identification of adenovirus. Sequencing of the one PCR-positive dragon showed 95% nucleotide sequence alignment with agamid atadenovirus 1. Further investigation involved testing the breeding population, including the parents of the affected juveniles. Blood and cloacal samples were collected from the adult population, DNA was extracted and tested by PCR for adenovirus. There was a high percentage of positive results from the samples collected from the breeding population. CONCLUSION: This is the first reported group outbreak of adenoviral disease in bearded dragons in Australia.

Tracheal resection and anastomosis in a red-tailed black cockatoo (Calyptorhynchus banksii banksii).

Tracheal stricture is an uncommon sequel to tracheitis in birds. We describe a case in a red-tailed black cockatoo that was attributed to a bacterial tracheitis associated with inhaled plant material and was successfully resolved by surgical resection and anastomosis of the trachea.

Keratoacanthoma causing beak deformity in a budgerigar (Melopsittacus undulatus).

This report describes a keratoacanthoma causing abnormal maxillary beak growth in a 6-year-old male budgerigar (Melopsittacus undulates). Although the bird was still capable of eating, it had recently been demonstrating signs of respiratory distress and euthanasia was recommended. On histological examination, the neoplasm was dramatically effacing the normal structure of the maxilla and infiltrating into the rostral nasal sinuses. The tumour consisted of many cyst-like proliferations of well-differentiated squamous epithelial cells with central keratinization. Contiguity of the tumour cells with the stratum germinativum of the beak was noted in one microscopic field. This tumour type has not previously been reported in the avian beak; however, this case shows some similarities to subungual keratoacanthomas occurring in human patients and nailbed keratoacanthomas occurring in dogs and cats.

Proventricular dilatation disease: an emerging exotic disease of parrots in Australia.

Proventricular dilatation disease is a viral disease seen as a segmental neuropathy in parrots. It has always been believed to be a disease exotic to Australia, with the only reported case being a legally imported Green Wing Macaw (Ara chloroptera) in 1993. This paper reports a cluster of cases seen in south-east Queensland in 2005 to 2006. Clinical signs, autopsy findings and histopathological findings are described. No pattern or common source for these cases could be identified. The implications for Australian aviculture and avifauna are discussed.

Avian cryptococcosis.

Clinical and laboratory findings in 15 unreported cases of avian cryptococcosis from Australia were collated and contrasted with 11 cases recorded in the literature. Cryptococcus species produced localized invasive disease of the upper respiratory tract of captive parrots living in Australia. This resulted in signs referable to mycotic rhinitis or to involvement of structures contiguous with the nasal cavity, such as the beak, sinuses, choana, retrobulbar space and palate. Parrots of widely differing ages were affected and of the seven birds for which sex was determinable, six were male. Cryptococcus bacillisporus (formerly C. neoformans var. gattii) accounted for four of five infections in which the species or variety was determinable, suggesting that exposure to eucalyptus material may be a predisposing factor. In these cases, Cryptococcus appeared to behave as a primary pathogen of immunocompetent hosts. One tissue specimen was available from an Australian racing pigeon with minimally invasive subcutaneous disease; immunohistology demonstrated a C. neoformans var. grubii (formerly C. neoformans var. neoformans serotype A) infection, presumably subsequent to traumatic inoculation of yeast cells into the subcutis. Two similar cases had been reported previously in pigeons domiciled in America. Data for parrots, one pigeon and other birds studied principally in America and Europe (and likely infected with C. neoformans) suggested a different pattern of disease, more suggestive of opportunistic infection of immunodeficient hosts. In this cohort of patients, the organism was not restricted to cool superficial sites such as the upper respiratory tract or subcutis. Instead, infections typically penetrated the lower respiratory tract or disseminated widely to a variety of internal organs. Finally, three captive North Island brown kiwis, one residing in Australia, the other two in New Zealand, died as a result of severe diffuse cryptococcal pneumonia (two cases) or widely disseminated disease (one case). C. bacillisporus strains were isolated from all three cases, as reported previously for another kiwi with disseminated disease in New Zealand.

Acute beak and feather disease in juvenile African Grey parrots--an uncommon presentation of a common disease.

Psittacine Beak and Feather Disease is commonly diagnosed all over the world as a viral disease of psittacine birds that primarily results in abnormalities of the feathers and beak. The clinical presentation of this disease varies between species and age groups, but in the majority of cases the course of the disease is chronic. This case report documents an acute form of the disease in African Grey parrots (Psittacus erithacus erithacus) that resulted in death without lesions in the feathers and beak.

Acute pancreatitis in parrots.

Acute pancreatitis was diagnosed in three parrots. Antemortem diagnosis of pancreatitis in the avian patient is rarely documented, and should be suspected in birds showing clinical signs attributable to abdominal pain or gastro-intestinal dysfunction. However, not all birds with confirmed pancreatitis display these signs. A serum amylase level greater than 1,500 U/L is suggestive of pancreatitis and pancreatic biopsy can be used to confirm a diagnosis. The aetiology of acute pancreatitis in parrots is discussed and a suggested treatment protocol is described.