OBJECTIVE To create an atlas of the normal CT anatomy of the head of blue-and-gold macaws (Ara ararauna), African grey parrots (Psittacus erithacus), and monk parakeets (Myiopsitta monachus). ANIMALS 3 blue-and-gold macaws, 5 African grey parrots, and 6 monk parakeets and cadavers of 4 adult blue-and-gold macaws, 4 adult African grey parrots, and 7 monk parakeets. PROCEDURES Contrast-enhanced CT imaging of the head of the live birds was performed with a 4-multidetector-row CT scanner. Cadaveric specimens were stored at −20°C until completely frozen, and each head was then sliced at 5-mm intervals to create reference cross sections. Frozen cross sections were cleaned with water and photographed on both sides. Anatomic structures within each head were identified with the aid of the available literature, labeled first on anatomic photographs, and then matched to and labeled on corresponding CT images. The best CT reconstruction filter, window width, and window level for obtaining diagnostic images of each structure were also identified. RESULTS Most of the clinically relevant structures of the head were identified in both the cross-sectional photographs and corresponding CT images. Optimal visibility of the bony structures was achieved via CT with a standard soft tissue filter and pulmonary window. The use of contrast medium allowed a thorough evaluation of the soft tissues. CONCLUSIONS AND CLINICAL RELEVANCE The labeled CT images and photographs of anatomic structures of the heads of common pet parrot species created in this study may be useful as an atlas to aid interpretation of images obtained with any imaging modality.

Objective: To evaluate the pharmacokinetics of nalbuphine decanoate after IM administration to Hispaniolan Amazon parrots (Amazona ventralis). Animals: 9 healthy adult Hispaniolan Amazon parrots of unknown sex. Procedures: Nalbuphine decanoate (37.5 mg/kg) was administered IM to all birds. Plasma samples were obtained from blood collected before (time 0) and 0.25, 1, 2, 3, 6, 12, 24, 48, and 96 hours after drug administration. Plasma samples were used for measurement of nalbuphine concentrations via liquid chromatography–tandem mass spectrometry. Pharmacokinetic parameters were estimated with computer software. Results: Plasma concentrations of nalbuphine increased rapidly after IM administration, with a mean concentration of 46.1 ng/mL at 0.25 hours after administration. Plasma concentrations of nalbuphine remained > 20 ng/mL for at least 24 hours in all birds. The maximum plasma concentration was 109.4 ng/mL at 2.15 hours. The mean terminal half-life was 20.4 hours. Conclusions and Clinical Relevance: In Hispaniolan Amazon parrots, plasma concentrations of nalbuphine were prolonged after IM administration of nalbuphine decanoate, compared with previously reported results after administration of nalbuphine hydrochloride. Plasma concentrations that could be associated with antinociception were maintained for 24 hours after IM administration of 37.5 mg of nalbuphine decanoate/kg. Safety and analgesic efficacy of nalbuphine treatments in this species require further investigation to determine the potential for clinical use in pain management in psittacine species.

Objective-To determine the pharmacokinetics of tramadol hydrochloride (30 mg/kg) following twice-daily oral administration in Hispaniolan Amazon parrots (Amazona ventralis). Animals-9 healthy adult Hispaniolan Amazon parrots. Procedures-Tramadol hydrochloride was administered to each parrot at a dosage of 30 mg/kg, PO, every 12 hours for 5 days. Blood samples were collected just prior to dose 2 on the first day of administration (day 1) and 5 minutes before and 10, 20, 30, 60, 90, 180, 360, and 720 minutes after the morning dose was given on day 5. Plasma was harvested from blood samples and analyzed by high-performance liquid chromatography. Degree of sedation was evaluated in each parrot throughout the study. Results-No changes in the parrots’ behavior were observed. Twelve hours after the first dose was administered, mean +/- SD concentrations of tramadol and its only active metabolite M1 (O-desmethyltramadol) were 53 +/- 57 ng/mL and 6 +/- 6 ng/mL, respectively. At steady state following 4.5 days of twice-daily administration, the mean half-lives for plasma tramadol and M1 concentrations were 2.92 +/- 0.78 hours and 2.14 +/- 0.07 hours, respectively. On day 5 of tramadol administration, plasma concentrations remained in the therapeutic range for approximately 6 hours. Other tramadol metabolites (M2, M4, and M5) were also present. Conclusions and Clinical Relevance-On the basis of these results and modeling of the data, tramadol at a dosage of 30 mg/kg, PO, will likely need to be administered every 6 to 8 hours to maintain therapeutic plasma concentrations in Hispaniolan Amazon parrots.

Objective: To assess the effects of dopamine and dobutamine on the blood pressure of isoflurane-anesthetized Hispaniolan Amazon parrots (Amazona ventralis). Animals: 8 Hispaniolan Amazon parrots. Procedures: A randomized crossover study was conducted. Each bird was anesthetized (anesthesia maintained by administration of 2.5% isoflurane in oxygen) and received 3 doses of each drug during a treatment period of 20 min/dose. Treatments were constant rate infusions (CRIs) of dobutamine (5, 10, and 15 μg/kg/min) and dopamine (5, 7, and 10 μg/kg/min). Direct systolic, diastolic, and mean arterial pressure measurements, heart rate, esophageal temperature, and end-tidal partial pressure of CO2 were recorded throughout the treatment periods. Results: Mean ± SD of the systolic, mean, and diastolic arterial blood pressures at time 0 (initiation of a CRI) were 132.9 ± 22.1 mm Hg, 116.9 ± 20.5 mm Hg, and 101.9 ± 22.0 mm Hg, respectively. Dopamine resulted in significantly higher values than did dobutamine for the measured variables, except for end-tidal partial pressure of CO2. Post hoc multiple comparisons revealed that the changes in arterial blood pressure were significantly different 4 to 7 minutes after initiation of a CRI. Overall, dopamine at rates of 7 and 10 μg/kg/min and dobutamine at a rate of 15 μg/kg/min caused the greatest increases in arterial blood pressure. Conclusions and Clinical Relevance: Dobutamine CRI at 5, 10, and 15 μg/kg/min and dopamine CRI at 5, 7, and 10 μg/kg/min may be useful in correcting severe hypotension in Hispaniolan Amazon parrots caused by anesthesia maintained with 2.5% isoflurane.

Avian chlamydiosis is caused by Chlamydophila psittaci and considered as one of an important zoonotic disease throughout the world. Among more than 400 avian species including poultry and pet birds susceptible to the disease, psittacine birds were known to be mostly susceptible hosts. In Korea, no outbreak of the disease and genetic analysis of the agent in poultry and pet birds have been reported. With histopathological findings and genetic identification of a causative agent, avian chlamydiosis was identified in parrots submitted from the same pet bird farm in 2006 and 2009 for the diagnosis. Based on genetic sequences and phylogenetic analysis of ompA gene, the two isolates of Chlamydophila psittaci showed 100% of genetic similarity and belonged to genotype A, suggesting that the same agent might be continuously circulated in the farm. This result indicates that serological survey of the disease in pet bird farms and impact of the disease on significance in public health may be further studied.

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.

Objective-To evaluate the antinociceptive effects and duration of action of nalbuphine HCl administered IM on thermal thresholds in Hispaniolan Amazon parrots (Amazona ventralis). Animals-14 healthy adult Hispaniolan Amazon parrots of unknown sex. Procedures-3 doses of nalbuphine (12.5, 25, and 50 mg/kg, IM) and saline (0.9% NaCl) solution (control treatment) were evaluated in a blinded complete crossover experimental design by use of foot withdrawal threshold to a noxious thermal stimulus. Baseline data on thermal threshold were generated 1 hour before administration of nalbuphine or saline solution; thermal threshold measurements were obtained 0.5, 1.5, 3, and 6 hours after administration. Results-Nalbuphine administered IM at 12.5 mg/kg significantly increased the thermal threshold (mean change, 2.4 degrees C), compared with results for the control treatment, and significantly changed thermal threshold for up to 3 hours, compared with baseline results (mean change, 2.6 degrees to 3.8 degrees C). Higher doses of nalbuphine did not significantly change thermal thresholds, compared with results for the control treatment, but had a significant effect, compared with baseline results, for up to 3 and 1.5 hours after administration, respectively. Conclusions and Clinical Relevance-Nalbuphine administered IM at 12.5 mg/kg significantly increased the foot withdrawal threshold to a thermal noxious stimulus in Hispaniolan Amazon parrots. Higher doses of nalbuphine did not result in significantly increased thermal thresholds or a longer duration of action and would be expected to result in less analgesic effect than lower doses. Further studies are needed to fully evaluate the analgesic effects of nalbuphine in psittacine species.

Objective-To compare serum concentrations of liposome-encapsulated butorphanol tartrate (LEBT) and standard butorphanol tartrate (STDBT) following SC and IM administration, respectively, and to evaluate analgesic effects of LEBT and STDBT after parenteral administration to Hispaniolan parrots. Animals-11 adult Hispaniolan parrots. Procedure-The ability of LEBT to prolong the duration of analgesia in an avian species was tested. Blood samples were collected at serial time points after SC administration of LEBT (10 mg/kg or 15 mg/kg) or IM administration of STDBT (5 mg/kg). Serum concentrations of butorphanol tartrate were determined by use of a commercial immunoassay that measured parent drug and metabolites. Analgesic efficacy was evaluated in parrots exposed to electrical and thermal stimuli. Foot withdrawal thresholds were recorded at baseline and at serial time points after LEBT (15 mg/kg), liposome vehicle, STDBT (2 mg/kg), or physiologic saline (0.9% NaCl) solution administration. Results-LEBT had a prolonged in vivo release for up to 5 days. Negligible serum butorphanol and butorphanol metabolite concentrations were obtained at 24 hours after IM administration of STDBT. Analgesic efficacy of LEBT as measured by foot withdrawal threshold to noxious thermal and electrical stimuli persisted for 3 to 5 days following SC administration of LEBT. Conclusions and Clinical Relevance-SC administration of LEBT provided analgesia and detectable serum butorphanol concentrations in Hispaniolan parrots for up to 5 days. The use of LEBT may allow for substantial improvement in long-term pain relief without subjecting birds to the stress of handling and multiple daily injections.

OBJECTIVE To compare the disposition of fentanyl citrate after a single IV injection in isoflurane-anesthetized red-tailed hawks (Buteo jamaicensis) and Hispaniolan Amazon parrots (Amazona ventralis). ANIMALS 6 adult red-tailed hawks and 6 adult Hispaniolan Amazon parrots. PROCEDURES Anesthesia was induced and maintained with isoflurane; intermittent positive-pressure ventilation was provided. The minimum alveolar concentration of isoflurane was determined for each bird by use of the bracketing method and a supramaximal electrical stimulus. Fentanyl (20 μg/kg) was administered IV. Arterial (red-tailed hawks) or jugular venous (Hispaniolan Amazon parrots) blood samples were obtained immediately before and 1, 2, 4, 8, 15, 30, 60, 120, 180, 240, and 480 minutes (red-tailed hawks) and 1, 5, 10, 15, 30, 60, 120, and 180 minutes (Hispaniolan Amazon parrots) after fentanyl administration. RESULTS A 3-compartment and a 2-compartment model best described fentanyl pharmacokinetics in red-tailed hawks and Hispaniolan Amazon parrots, respectively. Median apparent volume of the central compartment and volume of distribution at steady state were 222 mL/kg and 987 mL/kg, respectively, for the red-tailed hawks and 5,108 mL/kg and 13,079 mL/kg, respectively, for the Hispaniolan Amazon parrots. Median clearance and elimination half-life were 8.9 mL/min/kg and 90.22 minutes, respectively, for the red-tailed hawks and 198.8 mL/min/kg and 51.18 minutes, respectively, for the Hispaniolan Amazon parrots. CONCLUSIONS AND CLINICAL RELEVANCE Pharmacokinetic results for fentanyl in isoflurane-anesthetized red-tailed hawks and Hispaniolan Amazon parrots indicated large differences and should strongly discourage extrapolation of doses between these 2 species.

OBJECTIVE To determine pharmacokinetics of butorphanol tartrate incorporated into poloxamer 407 (P407) after SC administration to Hispaniolan Amazon parrots (Amazona ventralis). ANIMALS 11 adult Hispaniolan Amazon parrots (6 males and 5 females; 11 to 27 years old). PROCEDURES A sterile formulation of butorphanol in P407 (But-P407) 25% (percentage determined as [weight of P407/weight of diluent] × 100]) was created (8.3 mg/mL). Five preliminary experiments (2 birds/experiment) were performed to determine the ideal dose for this species. The formulation then was administered (12.5 mg/kg, SC) to 8 birds. Blood samples were collected before (time 0) and 0.08, 0.5, 1, 2, 4, 8, 12, and 24 hours after drug administration. Some birds were used more than once, with a washout period of ≥ 3 months between subsequent treatments. Butorphanol concentrations were quantitated by use of liquid chromatography-tandem mass spectrometry. Pharmacokinetic analysis was performed by use of noncompartmental analysis. RESULTS Maximal plasma butorphanol concentration was reached at 1.31 hours. Plasma concentrations of butorphanol remained > 100 ng/mL for > 3 hours (all birds) or > 4 hours (5/8 birds) but < 8 hours (all birds). Half-life of the terminal slope was 3.41 hours. No adverse effects were detected. CONCLUSIONS AND CLINICAL RELEVANCE Butorphanol was absorbed well from the But-P407 25% by Hispaniolan Amazon parrots, and absorption followed a pharmacokinetic profile compatible with a sustained-release drug. A dose of 12.5 mg/kg, SC, would theoretically provide analgesia for 4 to 8 hours. No adverse effects were detected. Studies on the pharmacodynamics of this formulation are necessary to confirm the degree and duration of analgesia.