An outbreak of chlamydiosis in captive blue-fronted Amazon parrots (Amazona aestiva) in Brazil.

Fifty-eight blue-fronted Amazon parrot (Amazona aestiva) nestlings, recovered from the illegal trade, became ill at a wildlife rehabilitation center in S?o Paulo State, Brazil. Clinical signs observed were nonspecific, and the mortality rate was 96.5% despite initial treatment with norfloxacin. Postmortem examinations were performed on 10 birds. Liver and spleen smears showed structures suggestive of Chlamydophila psittaci in four cases. Diagnosis was confirmed by seminested polymerase chain reaction on tissue samples. Other birds from the same location showed no clinical signs of the disease, although high complement fixation titers to C. psittaci were found in 10 adult psittacines. All birds in the facility were treated with doxycycline. The two surviving nestlings did not recover after two doxycycline treatments and were euthanatized. The high mortality rate observed in this outbreak was attributed to poor conditions of husbandry and delays in the diagnosis and treatment of the disease. After diagnosis, improved control measures for chlamydiosis were instituted.     

Chronic pulmonary interstitial fibrosis in a blue-fronted Amazon parrot (Amazona aestiva aestiva)

A 30-yr-old blue-fronted Amazon parrot (Amazon aestiva aestiva) was presented to the clinic with a history of sneezing more often during the last 2 mo. Physical examination revealed only a mild nasal discharge. Complete hematologic and plasma biochemical examination showed no abnormalities. Computerized tomography (CT) of the complete bird showed generalized lung alterations consistent with lung fibrosis. Two lung biopsies were taken. The results of the histologic examination of the biopsies confirmed the tentative CT diagnosis of pulmonary interstitial fibrosis. To our knowledge this is the first reported case of chronic pulmonary interstitial fibrosis diagnosed by means of a lung biopsy in an avian species. The histologic characteristics are discussed and compared with those of human idiopathic pulmonary fibrosis.     

A dermoid of the eye in a blue-fronted Amazon parrot (Amazona aestiva)

A corneo-conjunctival dermoid is reported in a blue-fronted Amazon parrot ( Amazona aestiva ). After laminar keratectomy, histology showed the epidermis with feather follicles and dermal connective tissue with lymph follicles and sebaceous glands.     

Computed tomographic and radiographic morphometric study of cardiac and coelomic dimensions in captive blue-fronted Amazon parrots (Amazona aestiva,Linnaeus, 1758) with varying body condition scores

This study aimed to assess radiographic and tomographic cardiac parameters, including width and length of the heart, and the ratio of heart width to coelom width of blue-fronted Amazon parrots (Amazona aestiva) with varying body condition scores. Thirty-five captive birds were included in the study and were allocated into one of three groups according to their respective body condition score: lean, ideal and obese. No differences were observed among the groups with regard to radiographic and tomographic measurements. Computed tomography enabled better identification of the structures of the cardiovascular system without interference from the overlying structures of the celomatic cavity observed in radiographic images. However, radiographic examinations should still be considered the standard screening method to identify cardiac alterations, such as increased or reduced organ dimensions. Standardizing the techniques and measurements performed in this study may serve as a basis for further research in the field.     

Cholangiocarcinoma in a blue-fronted Amazon parrot (Amazona estiva)

A case of cholangiocarcinoma in a 3-year-old blue-fronted Amazon parrot (Amazona estiva) is reported. Neoplastic tissue was limited to the liver, where it infiltrated and replaced much of the hepatic parenchyma. The only other reported cases of cholangiocarcinoma in an Amazon parrot (Amazona xanthops) also occurred in a bird in its fourth year of age.     

Effects of bilateral topical administration of repeated doses of rocuronium bromide as a mydriatic agent in Amazon parrots (Amazona aestiva and Amazona amazonica)

The effects of bilateral topical application of repeated doses of rocuronium in parrots are unknown, motivating this research. These effects were evaluated in 24 healthy adult Amazon parrots (12 Amazona aestiva and 12 Amazona amazonica). Three different doses of rocuronium bromide (10 mg/mL) were applied with a micropipette onto the cornea: a single instillation of 20 µL/eye; two instillations of 20 µL/eye, spaced 15 minutes apart; and three instillations of 20 µL/eye, spaced 15 minutes apart. Pupillary diameter (PD) was measured with a digital caliper before treatments (T0), every 15 minutes during the first hour postadministration (T15, T30, T45, T60), hourly for 6 hours (T120, T180, T240, T300, T360), and after 24 hours (T24h). Significant differences were observed between T0 and T15-T120 with a single instillation and between T0 and T15-T360 with double and triple instillations. The maximum median PDs were 3.47 mm (T45—one instillation), 3.88 mm (T45—two instillations), and 4.09 mm (T30—three instillations). PD returned to baseline at T180 with one instillation and at T24h with double and triple instillations. All protocols showed similar PD values at T0 and T24h. Transient lower eyelid paresis was the only adverse effect observed. Bilateral topical administrations of two and three repeated rocuronium bromide doses produced adequate mydriasis in Amazon parrots and may be indicated for longer ophthalmic procedures.     

Chlamydophila psittaci in free-living Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil

Chlamydophila psittaci (C. psittaci) infection was evaluated in 77 free-living nestlings of Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil. Tracheal and cloacal swab samples from 32 wild parrot and 45 macaw nestlings were submitted to semi-nested PCR, while serum samples were submitted to complement fixation test (CFT). Although all 32 Amazon parrot serum samples were negative by CFT, cloacal swabs from two birds were positive for Chlamydophila DNA by semi-nested PCR (6.3%); these positive birds were 32 and 45 days old. In macaws, tracheal and cloacal swabs were positive in 8.9% and 26.7% of the samples, respectively. Complement-fixing antibodies were detected in 4.8% of the macaw nestlings; macaw nestlings with positive findings were between 33 and 88 days old. These results indicate widespread dissemination of this pathogen in the two evaluated psittacine populations. No birds had clinical signs suggestive of chlamydiosis. To the best of our knowledge, this is the first report on C. psittaci in free-living Blue-fronted Amazon parrots and Hyacinth macaws in Brazil.     

Pilot study of echocardiographic studies using color- and pulsed-wave spectral Doppler methods in blue-crowned amazons (Amazona ventralis) and blue-fronted amazons (Amazona a. aestiva)

Colour-flow and pulsed-wave spectral Doppler echocardiography was performed on 6 healthy, adult Hispaniolan amazon parrots (Amazona ventralis) and 6 blue-fronted amazon parrots (Amazona a. aestiva) to establish normal reference values. Birds were anesthetized with isoflurane in oxygen and placed in dorsal recumbency. An electrocardiogram was recorded continuously and birds were imaged with a micro-phased-array scanner with a frequency of 7.0 MHz. After assessment of cardiac function in 2-D-echocardiography, blood flow across the left and the right atrioventricular valve and across the aortic valve was determined using color-flow and pulsed-wave spectral Doppler echocardiography. Diastolic inflow (mean value +/- standard deviation) into the left ventricle was 0.17 +/- 0.02 m/s (Hispaniolan amazons) and 0.18 +/- 0.03 m/s (Blue fronted amazons). Diastolic inflow into the right ventricle was 0.22 +/- 0.05 m/s (Hispaniolan amazons) and 0.22 +/- 0.04 m/s (Blue fronted amazons). Velocity across the aortic valve was 0.84 +/- 0.07 m/s (Hispaniolan amazons) and 0.83 +/- 0.08 m/s (Blue fronted amazons). Systolic pulmonary flow could not be detected in any of the birds in this study. No significant differences were evident between the two species examined. Results of this study indicate that Doppler echocardiography is a promising technique to determine blood flow in the avian heart. Further studies in other avian species are needed to establish reference values for assessment of cardiac function in diseased birds.     

Acetylcholinesterase concentrations in heparinized blood of Hispaniolan Amazon parrots (Amazona ventralis).

Organophosphate and carbamate pesticides inhibit acetylcholinesterase (AChE) at nerve synapses. Blood samples from 22 Hispaniolan Amazon parrots (Amazona ventralis) were assayed for cholinesterase levels by two different techniques. Using the modified Michel method, the whole-blood cholinesterase activity levels ranged from 0.082 to 0.616 deltapH/hr with a mean value of 0.35 deltapH/hr. A reference range (0.08-0.62 deltapH/hr) for cholinesterase was established in birds. The modified Ellman spectrophotometric method was used to measure AChE activity by adding acetylthiocholine or pseudocholinesterase (plasma cholinesterase) activity by adding butyrylthiocholine. The reference range of the AChE activity using the modified Ellman spectrophotometric method was 0-1.12 micromol/ml/min with a mean of 0.48 micromol/ml/min, and for pseudocholinesterase the range was 0.09-0.98 micromol/ml/min with a mean of 0.53 micromol/ml/min.     

Antinociceptive effects after oral administration of tramadol hydrochloride in Hispaniolan Amazon parrots (Amazona ventralis)

Objective-To evaluate antinociceptive effects on thermal thresholds after oral administration of tramadol hydrochloride to Hispaniolan Amazon parrots (Amazona ventralis). Animals-15 healthy adult Hispaniolan Amazon parrots. Procedures-2 crossover experiments were conducted. In the first experiment, 15 parrots received 3 treatments (tramadol at 2 doses [10 and 20 mg/kg] and a control suspension) administered orally. In the second experiment, 11 parrots received 2 treatments (tramadol hydrochloride [30 mg/kg] and a control suspension) administered orally. Baseline thermal foot withdrawal threshold was measured 1 hour before drug or control suspension administration; thermal foot withdrawal threshold was measured after administration at 0.5, 1.5, 3, and 6 hours (both experiments) and also at 9 hours (second experiment only). Results-For the first experiment, there were no overall effects of treatment, hour, period, or any interactions. For the second experiment, there was an overall effect of treatment, with a significant difference between tramadol hydrochloride and control suspension (mean change from baseline, 2.00° and -0.09°C, respectively). There also was a significant change from baseline for tramadol hydrochloride at 0.5, 1.5, and 6 hours after administration but not at 3 or 9 hours after administration. Conclusions and Clinical Relevance-Tramadol at a dose of 30 mg/kg, PO, induced thermal antinociception in Hispaniolan Amazon parrots. This dose was necessary for induction of significant and sustained analgesic effects, with duration of action up to 6 hours. Further studies with other types of noxious stimulation, dosages, and intervals are needed to fully evaluate the analgesic effects of tramadol hydrochloride in psittacines.