The purpose of this study was to determine the pharmacokinetics of cannabidiol (CBD), a potential treatment option that may alleviate pain in companion animals and humans, in the Hispaniolan Amazon parrot (Amazona ventralis). A pilot study administered a single oral dose of CBD in hemp oil at 10 mg/kg to 2 birds and 20 mg/kg to 2 birds. Because the maximum serum concentrations (C_max) for these doses were 5.5 and 13 ng/mL, respectively, and the serum half-life was 2 hours for both groups, the doses were considered too low for clinical use in this species. Therefore, a study was designed in which 14 healthy 12–14-year-old parrots of both sexes and weighing 0.24–0.35 kg (mean, 0.28 kg) were enrolled. Seven birds were administered 60 mg/kg CBD PO, and 7 birds were administered 120 mg/kg CBD PO. Blood samples were obtained at time 0, and at 0.5, 1, 2, 3, 4, 6, and 10 hours posttreatment in a balanced incomplete block design. Quantification of plasma CBD concentrations was determined by use of a validated liquid chromatography–mass spectrometry assay. Pharmacokinetic parameters were determined by noncompartmental analysis. The areas under the curve (h·ng/mL) were 518 and 1863, C_max (ng/ mL) were 213 and 562, and times to achieve C_max (hours) were 0.5 and 4 for the 60 and 120 mg/kg doses, respectively. The serum half-life could not be determined in the 60 mg/kg treatment, but was 1.28 hours at 120 mg/kg. Adverse effects were not observed in any bird. The highly variable results and short half-life of the drug in Hispaniolan Amazon parrots, even at high doses, suggests that this drug formulation was inconsistent in achieving targeted concentrations as reported in other animal species.

Meloxicam is a commonly prescribed non-steroidal anti-inflammatory drug for backyard poultry that has demonstrated pharmacodynamic efficacy at a single high dose of 5 mg/ kg. This study characterized the adverse effects of meloxicam administered in chickens at an approximate dose of 5 mg/kg orally twice daily for 5 days. Twenty-one adult Rhode Island Red hens (Gallus gallus domesticus), judged to be healthy based on an external physical examination, complete blood count (CBC), and plasma biochemistry panel, were recruited for this study. The subject birds were randomly assigned to a treatment (n = 11) or control group (n = 10) and received a 15-mg tablet of meloxicam or a nonmedicated feed pellet, respectively, orally twice daily. Physical examinations and body weight measurements were performed daily, and observation for clinical signs occurred twice daily. Following completion of the 5-day treatment course, an external physical examination, blood collection for a CBC and plasma biochemistry panel, euthanasia, necropsy, and measurement of meloxicam tissue residues were performed. During the treatment course, 1 hen from the treatment group died with peracute clinical signs, 2 hens from the treatment group died suddenly with no clinical signs, and 1 hen from the treatment group became acutely lethargic and was euthanized. Within the meloxicam group, 7 out of 11 hens had gross and histologic evidence of varying levels of renal acute tubular injury and gout. Plasma uric acid concentrations were above the species reference intervals in all affected hens in the treatment group that were still available for testing. The control group had no evidence of renal injury or gout based on postmortem examinations. Based on the results of this study, repeated oral dosing of meloxicam in chickens at 5 mg/kg twice daily is not recommended.

Backyard poultry are commonly treated in veterinary hospitals; however, there is limited information regarding appropriate dosing of medications and withdrawal times for eggs. Six healthy adult bantam Cochin hens were given a single oral dose of meloxicam (1 mg/kg). Meloxicam plasma concentrations and egg residues were analyzed by high-performance liquid chromatography. Noncompartmental analysis was used to calculate pharmacokinetic parameters. The apparent terminal half-life, maximum concentration, and time to maximum concentration were 5.94 ± 0.92 hours, 7.03 ± 2.68 µg/mL, and 2.83 ± 1.33 hours, respectively. Meloxicam was detected in egg whites for 4.8 ± 1.5 days and egg yolks for 9.8 ± 2.4 days. Results were compared with previous studies in white leghorn and Columbian Wyandotte hens. Bantam Cochin hens demonstrated a significantly longer mean apparent terminal half-life, greater area under the curve, smaller elimination rate constant, and longer egg residue times compared with white leghorn hens. However, the pharmacokinetic results from the bantam Cochin hens did not significantly differ from those reported for the Columbian Wyandotte hens. Until pharmacodynamic studies can be performed, dosing of oral meloxicam in bantam Cochins should follow recommendations for Columbian Wyandotte hens to reduce the likelihood of adverse effects. These results better inform appropriate dosing of meloxicam in domestic hens, as well as recommended withdrawal times for egg consumption.

The nutritional deficiencies of popular seed-based diets for captive psittacine birds have been linked to physical and psychological disease conditions in these species. However, bird owners often reject transitioning their pets to nutritionally complete pelleted diets because of concerns over the difficulty of diet conversion. To assess dietary conversion of psittacine birds from seed-based to pelleted diets, avian veterinarians presented 3 diet conversion methods to owners with birds of varying ages and species. The owners implemented their chosen conversion method at home and then received a survey when they successfully completed diet conversion or abandoned their attempt. “Birdies Choice” was a reward-based method in which birds were offered 3 different pelleted diets on a tabletop. If there was a positive interaction and the bird ate one or more of the diets, the bird was rewarded. The preferred pellet was then gradually transitioned into their food dishes. In the “Slow and Steady” method, pellets were alternated with familiar food at varying intervals to increase the birds' exposure to the pellets. The “Tough Love” method maximized exposure to new pellets by introducing a small portion of familiar food for a limited time, along with multiple dishes of new pellets. Survey results showed 96% of birds converted regardless of method, with 57.5% converting within the first 7 days. When conversion times were evaluated by life stage (juvenile, adult, and geriatric), sex, or bird family (Psittacidae, Cacatuidae, and Psittaculidae), differences noted between groups were not significant. The only variable significantly affecting time to conversion was method used, with Tough Love converting birds faster than the other methods. Ultimately, all 3 methods of dietary conversion were successful with the majority of birds during the first month of implementation. These results provide evidence-based information to owners and veterinarians to facilitate pellet conversion attempts for psittacine birds.

The appropriate recognition and assessment of pain in animals is an essential tool that can be used by veterinary professionals, rehabilitators, household caregivers, and others to provide supportive care and analgesia to patients. Although the use of behavioral, postural, and facial changes to recognize pain have been studied in popular domestic species such as dogs (Canis lupus familiaris), cats (Felis catus), and rabbits (Oryctolagus cuniculus), very little is known relative to avian species. The purpose of this article is to provide a literature review comprising structured searches on the topic of avian pain recognition. The emphasis of the searches were based on the behavioral and postural alterations that have thus far been explored. The literature review was performed in the months of August–September 2020 over 5 online databases: MEDLINE/ PubMed, CAB Direct, Biosis, Zoological Record, and Scopus. Additional “snowballing” was incorporated by looking at the references and articles that cited the 126 articles from the initial abstract and full-text screening. Of the 194 full-text articles reviewed, 132 sources of literature were included in the final analysis. From these 132 sources of literature, 31.8% were general review articles in which avian pain behaviors were described irrespective of species, with others being specific to a particular species (chickens 47.8%, turkeys 7.6%, parrots 3.8%, pigeons [Columba livia] 3%, raptors 3%, and “other” 3%—2 on ducks, 1 on emus [Dromaius novaehollandiae], and 1 on Eurasian blue tits [Cyanistes caeruleus]). Pain stimulus varied depending on species, although the vast majority of the pain stimuli involved welfare issues such as beak trimming, limb abnormalities, and keel bone fractures in chickens. Although information regarding this topic remains limited for many avian species, this review provides a more thorough understanding of behavioral indicators of pain in species such as chickens, turkeys, psittacines, pigeons, raptors, and select others. It is the hope that this review will motivate further interest and future analgesia research for the improvement of avian welfare.

The objective of this study was to compare the effects of anticoagulant and no anticoagulant on routine biochemical analytes in domestic pigeons (Columba livia domestica). Blood samples were obtained from 8 clinically healthy pigeons. The sample obtained from each bird was divided into 4 blood collection tubes containing either ethylenediaminetetraacetic acid (EDTA), lithium heparin, sodium citrate, or no anticoagulant. The concentrations of creatinine, uric acid, triglyceride, total cholesterol, glucose, phosphorus, calcium, magnesium, total protein, albumin, and iron, and the activities of alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), were measured in blood from each of the blood collection tubes. The values of the measured parameters, with the exception of iron, were significantly lower in the citrated plasma samples compared with the serum samples, even after correcting for dilution. In the lithium heparin plasma samples, significant decreases in albumin, triglyceride, calcium, total cholesterol, and ALP, and a significant increase in iron, were observed compared with the values in the serum samples. The concentrations of total protein, creatinine, glucose, total cholesterol, triglyceride, magnesium, calcium, and phosphorus, as well as the activities for AST and ALP, were significantly lower in the EDTA plasma samples compared with the serum samples. In conclusion, the anticoagulants had significant effects on most of the measured parameters compared with serum. The findings of the present study suggest that a lithium heparin sample is the most appropriate plasma sample for the measurement of blood biochemical parameters in the domestic pigeon.

Fluoroscopic angiography evaluates the heart and vascular tree in real time and can be recorded for further diagnostic analysis and measurements. Although reports have been published of the use of fluoroscopic angiography in birds, this technique has not been evaluated in any avian species. The purpose of this study was to evaluate a fluoroscopic angiography protocol in 12 adult Hispaniolan Amazon parrots (Amazona ventralis). Under general anesthesia, the birds were positioned in right lateral (LAT) recumbency on a fluoroscopy table. A bolus of nonionic iodinated contrast agent was injected through a catheter inserted into the basilic or medial metatarsal vein during video acquisition. The same bolus was repeated to obtain the ventrodorsal (VD) view with the bird placed in dorsal recumbency. Eleven studies were performed. A total of 19 (10 VD, 9 LAT) continuous, real-time, fluoroscopic angiograms were successfully captured. The brachiocephalic trunk, aorta, pulmonary arteries, pulmonary veins, and caudal vena cava were visualized, and selected intraluminal measurements collected. The intraobserver and interobserver variability for 3 observers was calculated. Intraobserver agreement was found to be near perfect (intraclass correlation coefficient ≥0.95), whereas interobserver agreement was moderate to substantial (intraclass correlation coefficient ≥0.52). Coefficients of variation were excellent (VD 0.99, LAT 0.99) for intraobserver assessments and moderate (VD 0.72, LAT 0.52) for interobserver assessments. For the interobserver assessments, the VD projection measurements performed better than the LAT measurements. These results suggest that although there was some variation between different observers, relatively consistent vascular measurements could be obtained. The described fluoroscopic angiography protocol is a repeatable and reliable technique that could be useful for the diagnosis and monitoring of cardiovascular diseases in birds.

Regional limb perfusion (RLP) has been used to treat cases of distal limb infections in avian species. Potentially nephrotoxic drugs, such as amikacin, may increase the risk of nephrotoxicity with RLP because of the presence of the renal portal system and direct venous blood flow from the pelvic limbs to the kidneys. In a randomized, blinded, placebo-controlled study, the safety of repeated amikacin administration (20 mg/kg q24h for 3 doses) via RLP was evaluated in healthy female chickens (Gallus gallus domesticus; n = 8 treatment, n = 8 saline control group). Plasma uric acid concentrations were not significantly elevated in treated birds compared with the control group at any time point following RLP. One week following the final RLP, birds were necropsied and the kidneys evaluated grossly and histologically. There was no significant difference in renal pathology scores between treated and control birds or between kidneys ipsilateral to the perfused limb and contralateral kidneys. This study concludes that RLP of amikacin at high doses produced no discernable renal pathology in healthy euhydrated chickens.

Twelve adult burrowing owls (Athene cunicularia) maintained in a managed environment underwent complete bilateral ophthalmic examinations to assess ocular parameters and, if present, describe lesions (n = 24 eyes). Tear production was measured with a Schirmer tear test (STT), and intraocular pressure (IOP) was measured with rebound tonometry using established calibration settings (D = dog/cat, P = other species). Retinography was performed for all birds after application of topical rocuronium bromide, and corneal diameter was measured. Menace response was absent bilaterally in 7 of 12 (58.3%) owls; however, this did not appear to be related to the presence of fundic lesions. Ocular lesions were visualized in 6 of 12 (50%) owls. The most common ophthalmic abnormality noted was mild multifocal fundic pigment clumping, suggestive of chorioretinal scarring. Other ocular lesions included 1 retinal tear and 1 incipient cataract. Mean tear production was 6.1 ± 3.0 mm/min. Mean IOPs were 11.6 ± 1.8 mm Hg and 7.1 ± 1.3 mm Hg for the D and P settings, respectively, and these were significantly different (P < 0.001). The IOP results did not differ significantly based on patient age or between the right and left eyes, but a higher mean was obtained from males versus females using the D setting (P < 0.039; male mean 12.1 ± 1.9 mm Hg; female mean 10.9 ± 1.2 mm Hg). Measurements obtained from the STT were not affected by either age or sex. Corneal height was 11 mm and width was 12 mm, regardless of age or sex. The rebound tonometer D setting is recommended for measuring IOP values in this species. Burrowing owls had inconsistent mydriasis following topical rocuronium bromide application to the eye; however, a complete fundic examination was possible with or without complete mydriasis.

A 16-year-old male Congo African grey parrot (Psittacus erithacus) was presented with an ulcerated wing mass that was excised and diagnosed on histopathology as squamous cell carcinoma (SCC). A second surgery was performed to completely excise the tumor margins, resulting in over 5 years of remission for the neoplasm. However, over the next 6 years the patient developed SCC in 3 new locations on the body, as well as 2 squamous papillomas. The 2 papillomas were surgically excised and did not recur. Due to their size and location, none of the 3 new SCCs were amenable to complete excision. Instead, the 3 SCCs were managed with a series of treatments with intralesional carboplatin in poloxamer 407 and carbon dioxide surgical laser debridements. This treatment regimen has resulted in long-term (52 months, 30 months, and 17 months) resolution for all 3 of the SCCs. The overall survival time for the patient, from the initial diagnosis to the time of this report, is over 2900 days. While being treated for the 3 SCCs, the African grey parrot had no overt signs of complications or adverse side effects.

1.5-year-old yellow-collared macaw (Primolius auricollis) was presented as a referral case for chronic breathing difficulties and coelomic distension. The bird was in poor body condition, and coelomic distension and green-colored urates were noted during the physical examination. Radiographic images revealed a large coelomic space-occupying soft-tissue lesion that was ultrasonographically confirmed to be hepatomegaly; the liver had a heterogeneous echogenic pattern. An ultrasound-guided fine needle aspirate of the liver was performed. The cytological results revealed immature hematopoietic cells with signs of dyserythropoiesis and were consistent with extramedullary hematopoiesis (EMH). The plasma biochemistry panel revealed a marked increase in aspartate aminotransferase and bile acids, consistent with severe hepatic disease. Following the results of the diagnostic tests, chemotherapy was initiated using hydroxyurea. Two weeks after the initial presentation and treatment, the bird died and a full postmortem examination was performed. Macroscopic examination confirmed severe hepatomegaly and severe splenomegaly. Histopathological examination of tissue samples confirmed severe EMH in the liver and spleen, splenic and renal hemosiderosis, and acute pulmonary congestion. The bone marrow was normal. The final diagnosis was pathogenic idiopathic EMH, and this case was unusual in both its presentation and severity. Extramedullary hematopoiesis is usually related to myeloid proliferative disorder, chronic blood loss, hemolytic disease, or chronic inflammatory disease. Mycobacteriosis and parasitic infection have been reported to be associated with EMH in birds; however, the inflammatory patterns seen in those cases were lacking in this case. Myeloproliferative neoplasia also appears an unlikely disease condition in this case considering that histopathology found normal architecture in the studied bone marrow; however, bone marrow abnormalities in locations other than the one sampled could not be excluded. A short review of homeostatic and pathogenic hematopoiesis in birds is provided to support the likely diagnosis of idiopathic EMH.

A 15-year-old female peach-faced lovebird (Agapornis roseicollis) was presented to the hospital for a possible left wing injury and an inability to fly after falling in its cage. On physical examination the left elbow was swollen and painful. Radiographic images revealed left wing soft tissue swelling surrounding the elbow and lysis of the distal humerus with extensive cortical thinning. Subsequent high-definition volumetric-imaging 3-dimensional computed tomography (HDVI 3D CT) revealed a pathological fracture, cortical lysis, periosteal reaction, and abnormal intraosseous soft tissue of the left humerus with associated soft tissue swelling, suggestive of neoplasia. No evidence of metastatic disease was identified. Surgical amputation of the left wing was elected. A liposarcoma and pathologic fracture of the humerus were diagnosed histologically and by oil red O staining for lipids in the neoplastic cells. The morphologic features of the tumor suggested that it developed within the adipocyte component of the medullary bone. The incision at the amputation site healed without complication. A follow-up HDVI 3D CT performed 4 months postsurgery showed no evidence of metastatic disease. To the authors' knowledge, this is the first report of a primary liposarcoma of medullary bone origin in an avian species.