Multisite integumentary squamous cell carcinoma in an African grey parrot (Psittacus erithacus erithacus)

A 22-year-old male African grey parrot (Psittacus erithacus erithacus) had had episodes of chronic feather picking and self-mutilation for 10 years; it had a 5 cm diameter right axillary wound and a 2 cm left dorsal patagial wound. Initial treatment with azithromycin and wound management was unsuccessful. Biopsies of both masses indicated squamous cell carcinoma. The left patagial tumour was removed completely by electrocautery. Cisplatin was administered weekly into multiple sites on the right axillary tumour and it initially appeared to regress; however, the bird's condition deteriorated after a month of treatment, and it was euthanased. The tumour was confirmed postmortem to be squamous cell carcinoma, which had invaded local tissues. The aetiology of the carcinoma may have been secondary to chronic focal trauma.     

Analgesic effects of butorphanol and buprenorphine in conscious African grey parrots (Psittacus erithacus erithacus and Psittacus erithacus timneh)

OBJECTIVE: To evaluate effects of butorphanol tartrate and buprenorphine hydrochloride on withdrawal threshold to a noxious stimulus in conscious African grey parrots. ANIMALS: 29 African grey parrots (Psittacus erithacus erithacus and Psittacus erithacus timneh). PROCEDURE: Birds were fitted with an electrode on the medial metatarsal region of the right leg, placed into a test box, and allowed to acclimate. An electrical stimulus (range, 0.0 to 1.46 mA) was delivered to each bird's foot through an aluminum perch. A withdrawal response was recorded when the bird lifted its foot from the perch or vigorously flinched its wings. Baseline threshold to a noxious electrical stimulus was determined. Birds then were randomly assigned to receive an i.m. injection of saline (0.9% NaCl) solution, butorphanol (1.0 mg/kg of body weight), or buprenorphine (0.1 mg/kg), and threshold values were determined again. RESULTS: Butorphanol significantly increased threshold value, but saline solution or buprenorphine did not significantly change threshold values. CONCLUSIONS AND CLINICAL RELEVANCE: Butorphanol had an analgesic effect, significantly increasing the threshold to electrical stimuli in African grey parrots. Buprenorphine at the dosage used did not change the threshold to electrical stimulus. Butorphanol provided an analgesic response in half of the birds tested. Butorphanol would be expected to provide analgesia to African grey parrots in a clinical setting.     

Blindness as a sign of proventricular dilatation disease in a grey parrot (Psittacus erithacus erithacus)

An approximately eight-year-old female grey parrot (Psittacus erithacus erithacus) was presented with a two months history of blindness. The radiographic examination showed a dilatation of the proventriculus, ventriculus and gut. Ophthalmoscopy and electroretinography revealed degeneration of the retina. A proventricular dilatation disease was suspected. The bird was euthanased because of deteriorating condition and poor prognosis. The pathological examination showed an atrophy of the ventricular muscles and lymphoplasmacytic infiltrates of the myenteric plexus of the proventriculus, ventriculus and gut as well as moderate lymphoplasmacytic infiltrates of the cerebrum with moderate neuronophagia. Lymphoplasmacytic infiltrates in the retina, indicating proventricular dilatation disease, and subsequent retinal degeneration were found. A potential common aetiology for proventricular dilatation disease and blindness is discussed.     

Severe leukopenia and liver necrosis in young African grey parrots (Psittacus erithacus erithacus) infected with psittacine circovirus

This paper describes the signs, clinical pathology, and postmortem findings in 14 young African grey parrots (Psittacus erithacus erithacus) that were naturally infected with psittacine beak and feather disease (PBFD) virus (psittacine circovirus). All but two of the parrots had severe leukopenia at clinical presentation. Two other parrots also had severe anemia. All birds died within 3 wk after presentation. Postmortem examination documented liver necrosis in 11 of 14 birds and secondary bacterial or fungal infections in 9 of 14 birds. Tests for Chlamydia psittaci, polyomavirus, and Salmonella sp. were negative. PBFD viral infection could be demonstrated in all birds by polymerase chain reaction. Supporting evidence of PBFD viral infection was gathered by histologic examination of the bursa of Fabricius, electron microscopy, and DNA in situ hybridization. Electron microscopic examination of both the bursa of Fabricius and liver revealed virus particles resembling circovirus. DNA in situ hybridization of six liver tissue samples confirmed the presence of PBFD virus and excluded the presence of avian polyomavirus. Our findings suggest that a specific presentation of peracute PBFD viral infection, characterized by severe leukopenia, anemia, or pancytopenia and liver necrosis in the absence of feather and beak abnormalities, may occur in young African grey parrots.     

Congenital extra-hepatic biliary cyst in a Congo African Grey Parrot (Psittacus erithacus erithacus)

An 8-week-old Congo African Grey Parrot (Psittacus erithacus erithacus) was presented with a history of abdominal enlargement since hatch. Trans-illumination of the abdomen suggested that the enlargement was due to marked hepatomegaly. This was supported by radiographic and ultrasonic examination. Postmortem examination revealed an extra-hepatic biliary cyst 4 cm in diameter.     

Prevalence and Risk Factors of Feather Plucking in African Grey Parrots (Psittacus erithacus erithacus and Psittacus erithacus timneh) and Cockatoos (Cacatua spp.)

Feather plucking, or the removal by a parrot of its own feathers, is thought to be one of the most common behaviour presentations in veterinary practices that treat avian patients. However, its aetiology is poorly understood. The aims of this study were to estimate the prevalence of feather plucking within the population of African grey parrots (Psittacus erithacus erithacus and Psittacus erithacus timneh) and cockatoos (Cacatua spp.) registered with 9 veterinary practices in the United Kingdom (UK) and to explore the association between frequently hypothesised risk factors and feather plucking in these species. A questionnaire was sent to the owners of 400 African grey parrots and 310 cockatoos registered with 9 UK veterinary practices. Returned questionnaires from 137 African grey parrots and 92 cockatoos were analysed, of which 39.4% of African grey parrots and 42.4% of cockatoos had exhibited feather-plucking behaviour at some point in their lifetime. Multivariable logistic regression modelling demonstrated that increasing hours of sleep and length of ownership were significantly associated (P < 0.05) with feather plucking in African grey parrots. Pet shop origin, cage location against ≥1 wall and ≥1 vacation taken by owners each year were significantly associated (P < 0.05) with feather plucking in cockatoos. The high prevalence of feather plucking in these commonly kept pets highlights this problem as a welfare concern, whereas the risk factor analysis challenges many frequently cited hypotheses regarding its aetiology. Further research is required to explore whether there is a causal relationship between the significant risk factors identified in this study and feather-plucking behaviour.     

Pharmacokinetics of voriconazole after oral administration of single and multiple doses in African grey parrots (Psittacus erithacus timneh)

OBJECTIVE: To determine the pharmacokinetics and safety of orally administered voriconazole in African grey parrots. ANIMALS: 20 clinically normal Timneh African grey parrots (Psittacus erithacus timneh). PROCEDURES: In single-dose trials, 12 parrots were each administered 6, 12, and 18 mg of voriconazole/kg orally and plasma concentrations of voriconazole were determined via high-pressure liquid chromatography. In a multiple-dose trial, voriconazole (18 mg/kg) was administered orally to 6 birds every 12 hours for 9 days; a control group (2 birds) received tap water. Treatment effects were assessed via observation, clinicopathologic analyses (3 assessments), and measurement of trough plasma voriconazole concentrations (2 assessments). RESULTS: Voriconazole's elimination half-life was short (1.1 to 1.6 hours). Higher doses resulted in disproportional increases in the maximum plasma voriconazole concentration and area under the curve. Trough plasma voriconazole concentrations achieved in the multiple-dose trial were lower than those achieved after administration of single doses. Polyuria (the only adverse treatment effect) developed in treated and control birds but was more severe in the treatment group. CONCLUSIONS AND CLINICAL RELEVANCE: In African grey parrots, voriconazole has dose-dependent pharmacokinetics and may induce its own metabolism. Oral administration of 12 to 18 mg of voriconazole/kg twice daily is a rational starting dose for treatment of African grey parrots infected with Aspergillus or other fungal organisms that have a minimal inhibitory concentration for voriconazole < or = 0.4 microg/mL. Higher doses may be needed to maintain plasma voriconazole concentrations during long-term treatment. Safety and efficacy of various voriconazole treatment regimens in this species require investigation.     

Pharmacokinetics of meloxicam after intravenous,intramuscular and oral administration of a single dose to African grey parrots (Psittacus erithacus)

Meloxicam is a nonsteroidal anti‐inflammatory drug commonly used in avian species. In this study, the pharmacokinetic parameters for meloxicam were determined following single intravenous (i.v.), intramuscular (i.m.) and oral (p.o.) administrations of the drug (1 mg/kg·b.w.) in adult African grey parrots (Psittacus erithacus; n = 6). Serial plasma samples were collected and meloxicam concentrations were determined using a validated high‐performance liquid chromatography assay. A noncompartmental pharmacokinetic analysis was performed. No undesirable side effects were observed during the study. After i.v. administration, the volume of distribution, clearance and elimination half‐life were 90.6 ± 4.1 mL/kg, 2.18 ± 0.25 mL/h/kg and 31.4 ± 4.6 h, respectively. The peak mean ± SD plasma concentration was 8.32 ± 0.95 μg/mL at 30 min after i.m. administration. Oral administration resulted in a slower absorption (t_max = 13.2 ± 3.5 h; C_max = 4.69 ± 0.75 μg/mL) and a lower bioavailability (38.1 ± 3.6%) than for i.m. (78.4 ± 5.5%) route. At 24 h, concentrations were 5.90 ± 0.28 μg/mL for i.v., 4.59 ± 0.36 μg/mL for i.m. and 3.21 ± 0.34 μg/mL for p.o. administrations and were higher than those published for Hispaniolan Amazon parrots at 12 h with predicted analgesic effects.     

Unusual tracheal foreign body in an African grey parrot.

This case report documents an unusual tracheal foreign body (a moth) in Congo African grey parrot (Psittacus erithacus erithacus). Gross postmortem signs and histopathology results are presented. A discussion of the peculiar avian anatomy that may have contributed to the aspiration of the moth is provided.