Evaluation of Thermal Antinociceptive Effects of Intramuscular Hydromorphone Hydrochloride in Great Horned Owls (Bubo virginianus).

Across the Americas, great horned owls (Bubo virginianus) are often presented to veterinarians for conditions requiring pain management. Although recent studies have evaluated opioid drugs in raptor species, information in Strigiformes is lacking. The objective of this study was to evaluate the analgesic effect and duration of action of hydromorphone hydrochloride, a full µ-opioid receptor agonist, in great horned owls. In a randomized, blinded, balanced crossover study, 6 adult birds (5 females and 1 male) received hydromorphone (0.3 and 0.6 mg/kg) or saline (0.9% NaCl) solution (0.03 mL/kg; control) in the left pectoral muscle, with a 7-day washout interval between treatments. Each bird was assigned an agitation-sedation score, and the thermal foot withdrawal threshold (TFWT) was measured at predetermined times before (t = 0 hours) and after treatment administration (t = 0.5, 1.5, 3, and 6 hours). Measurements of the TFWT were obtained with a test box equipped with a thermal perch, which delivered a gradually increasing temperature 40-62°C (104-143.6°F) to the right plantar surface of the owl's foot. Compared with controls, hydromorphone at 0.3 mg/kg dose resulted in significantly higher mean TFWT at 0.5 hours (P < 0.001), 1.5 hours (P = 0.003), and 3 hours (P = 0.005), whereas the 0.6 mg/kg dose resulted in significantly higher mean TFWT from 0.5 hours (P = 0.035) to 1.5 hours (P = 0.001). Both hydromorphone doses were associated with a significant change in the agitation-sedation score (P = 0.001), consistent with mild to moderate sedation. Two owls were observed tremoring after administration of the 0.6 mg/kg dose, which was not noted after the 0.5-hour timepoint; no other adverse effects were identified. This study offers scientific evidence to support the use of a µ-opioid agonist in great horned owls for pain management. Pharmacokinetics and other pharmacodynamic studies of other pain models evaluating hydromorphone and other opioid drugs in this species are still needed.

Evaluation of a Fluoroscopic Angiography Protocol in Hispaniolan Amazon Parrots (Amazona ventralis).

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.

Recognition and Assessment of Pain-Related Behaviors in Avian Species: An Integrative Review.

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.

Crotalid Polyvalent F(ab)2 Antivenom Treatment in a Red-Tailed Hawk (Buteo jamaicensis).

Envenomation in avian species can result in death, with few cases of successful treatment described. A juvenile, wild-caught, intact female red-tailed hawk (Buteo jamaicensis) used in falconry was presented for emergency evaluation after being bitten by a Northern Pacific rattlesnake (Crotalus oreganus) approximately 2 hours before presentation. On presentation, the bird was quiet, alert, and responsive, with moderate swelling and discomfort of the digits on the right foot. Complete blood count (CBC) and plasma biochemistry abnormalities included a regenerative left shift, severe lymphopenia, and a moderate hypoproteinemia characterized by moderate hypoalbuminemia. Analgesic and antibiotic medications were administered during hospitalization. In addition, 5 mL of VenomVet was administered intravenously with crystalloid fluids over 60 minutes; no adverse effects were noted secondary to infusion. Improvement in the swelling was observed immediately after antivenom administration and nearly resolved within 12 hours. Complete resolution of digital swelling with no discomfort on palpation of that foot was observed 1 week after initial presentation. Blood collected at the 1 week reexamination was submitted for a CBC and plasma biochemistry panel. The results of the CBC revealed a reduced regenerative left shift, increased heterophil count, and a moderate monocytosis; the lymphopenia was resolved. A mild hypoalbuminemia still persisted. Ten months after presentation, the bird was reported to be doing well with no changes in function of the right foot and subsequently released from captivity.

NEOURETEROCYSTOSTOMY AND URETHRAL STENT PLACEMENT IN A BLACK-HANDED SPIDER MONKEY (ATELES GEOFFROYI).

A 27-y-old female black-handed spider monkey (Ateles geoffroyi) was evaluated 13 d after an ovariohysterectomy because of abdominal distension, anorexia, and absent urination. The animal was diagnosed with a uroabdomen and urethral obstruction from computed tomographic findings and fluid creatinine levels. During exploratory laparotomy, a defect in the right ureter was confirmed as the source of the uroabdomen. Utilizing intraoperative fluoroscopy, a urethral obstruction with an irregular luminal filling defect was evident. A self-expanding nitinol urethral stent was placed, and a ureteral transposition was performed. Two months after the procedure, the animal developed dysuria, a urinary tract infection, recurrent bladder distension and a partial urethral obstruction. Treatment with prazosin 1 mg/kg PO q12h improved urination. Reobstruction of the urethra occurred 17 mo postsurgery, and the animal was euthanatized. On postmortem examination, the animal had ingrowth into the stent with proliferative granulation tissue, detrusor muscle degeneration, pelvic adhesions, cystitis, pyelonephritis, and hydronephrosis.

Altered prolactin and androgen receptors expression in companion rat benign mammary tumours.

Benign mammary tumours are among the most common tumours of companion rats (Rattus norvegicus domestica), as well as a major animal welfare concern and euthanasia. The first objective of this study was to evaluate the expression of oestrogen, progesterone, androgen, and prolactin receptors in neoplastic and normal mammary gland tissues and compare the expression of these receptors between groups. The second objective was to determine if the expression of these receptors in neoplastic mammary gland tissue correlates with overall survival and occurrence of an additional mass after initial mammary mass excision. The third objective was to determine if the expression of oestrogen, progesterone, androgen and prolactin receptors was associated with mammary tumor clinical parameters or with the age of the animals. Thirty-two benign mammary tumours were collected from companion rats and submitted for immunohistochemistry staining of prolactin receptor, oestrogen receptor alpha (ERa), progesterone and androgen receptors (AR). Allred score were obtained for mammary tumours (n = 32) and surrounding normal mammary tissue (n = 20) when present. Prolactin receptor expression increased significantly with mammary gland tumorigenesis (P < .0001), while AR expression decreased with tumorigenesis (P < .0001). Lower expression of ERa in tumor stroma was associated with shorter survival (P = .02). Hormonal receptor expression was not significantly associated with age, mass diameter, location nor likelihood of additional mass development. Further studies should investigate the effects of prolactin antagonists in a prospective study involving companion rats with benign mammary tumours.

Pilot Study: Correlation of the Surface Skin Temperature Between the Leg and Foot Using Thermographic Imaging in Captive Hawks.

The purpose of this study was to determine whether the thermal image temperatures of the tibiotarsal scaled region of the raptor leg and the plantar surface of ipsilateral foot while perching were correlated. The correlation between leg and foot temperature was sought to determine whether remote imaging of the legs can be used as a reliable predictor of foot temperature. The right and left tarsometatarsal region (Leg) and metatarsal pad (Foot) of 10 captive hawks, including 8 red-tailed hawks (Buteo jamaicensis), 1 Harris's hawk (Parabuteo unicinctus), and 1 Swainson's hawk (Buteo swainsoni) were imaged once daily over 3 consecutive days. To account for conditions of the metatarsal pad that might affect the thermal image, 3 groups were identified: Normal, Active when mild hyperemia was present, and Suspect when abrasions were noted. A significant correlation was evident when thermography readings of the tarsometatarsal region (R.Leg and L.Leg) of the unrestrained bird were compared with readings from the plantar surface of the ipsilateral metatarsal pad when restrained (R.Foot and L.Foot). The correlations for R.Leg versus R.Foot (r = 0.81) and L.Leg versus L.Foot (r = 0.74) suggest that temperatures of the tarsometatarsal region of perching hawks measured by infrared thermography may be useful to screen and monitor for the presence of thermal changes associated with inflammation of the metatarsal pad in captive hawk species.

Evaluation of Orally Administered Atorvastatin on Plasma Lipid and Biochemistry Profiles in Hypercholesterolemic Hispaniolan Amazon Parrots (Amazona ventralis).

Atorvastatin is a synthetic statin administered in its active form and used for the treatment of dyslipidemias. In the current study, the effects of atorvastatin were evaluated on plasma lipid profiles and the potential for adverse effects after once daily PO dosing of atorvastatin for 30 days in Hispaniolan Amazon parrots (Amazona ventralis). Sixteen adult parrots (10 female, 6 male) with hypercholesterolemia were used for this study. Birds were assigned to 2 groups (treatment and control) of 8 parrots each (3 male, 5 female) after balancing for age, sex, originating institution, and baseline plasma cholesterol values. Compounded atorvastatin oral suspension (10 mg/kg) was administered PO once daily via gavage into the crop. Equivalent volumes of placebo suspension were administered to the control group. Plasma biochemistry and plasma lipid profile analysis (total cholesterol, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides [TGs]) were analyzed on days 0, 14, and 30. Plasma samples and HDL-C fractions were evaluated for cholesterol and TG concentrations via enzymatic assays. Subtraction of HDL-C values from total cholesterol yielded the non-HDL-C concentration for each bird. Birds were routinely assessed for appetite, activity, and urofeces. Plasma atorvastatin concentrations were obtained from 7 of 8 birds in the treatment group from banked samples. Those samples were obtained on days 14 and 30, with drug administration 6 to 8 hours before collection. No significant differences were observed in total cholesterol, HDL-C, non-HDL-C, or TG between treatment and control groups at days 0, 14, and 30. Plasma atorvastatin concentrations were variable on day 14 (0.54-5.41 ng/ mL for 6 of 7 samples, with 1 outlier of 307 ng/mL) and on day 30 (0.79-6.74 ng/mL). No adverse effects were noted in any of the birds during the study period. When dosed PO at 10 mg/kg once daily, atorvastatin did not result in significant changes to plasma lipid profiles (eg, lowering of plasma total or non-HDL-C concentrations) at any time point during this study. Future studies to investigate pharmacokinetic and pharmacodynamic properties of atorvastatin in parrots may require increased doses and/or frequency of administration.

Modified Tail Amputation Technique in a Blue and Gold Macaw (Ara ararauna) With Uropygial Gland Adenocarcinoma.

A 33-year-old male blue and gold macaw (Ara ararauna) presented with a 5-month history of an ulcerated lesion and feather loss at the tail base. Two 4-mm biopsies obtained by the primary care veterinarian were consistent with uropygial gland adenocarcinoma. The bird was examined at the Veterinary Medical Teaching Hospital, University of California, and on physical evaluation, the dorsal and ventral surface of the tail base were devoid of feathers, ulcerated and crusted without an identifiable uropygial gland. Complete blood count, plasma biochemistry panel, whole-body radiographs, and an echocardiogram were performed before surgery. The bird was anesthetized, and a complete amputation of the tail was performed. The skin was incised with a radiofrequency electrosurgical system approximately 2 mm circumferentially cranial to the diseased tissue. The musculature was transected to the level of the vertebral column, disarticulating between the second and third caudal vertebrae and transecting the spinal cord with a no. 15 blade. Lateral vertebral processes of the second vertebra were removed with a rongeur. Coccygeus lateralis muscles and tensor fasciae latae muscles and skin were closed laterolaterally with 2 layers and 3-0 polydioxanone suture. The bird recovered uneventfully and was discharged after 6 days of hospitalization. The histopathological diagnosis was adenocarcinoma with squamous differentiation, marked scirrhous response, and superficial epithelial ulceration. It was determined that narrow margins of unaffected tissue were achieved from the pathological examination of submitted material. The bird was evaluated 24 days after surgery and again 3.5 months after surgery, without evidence of complications or recurrence. Approximately 10 days after the last reexamination, the bird was euthanatized after being found minimally responsive at home. A postmortem examination was not performed.

A novel surgical technique for enucleation in rabbits to reduce the risk of intra- and post-operative orbital hemorrhage.

A 10-year-old male castrated Holland Lop rabbit (Oryctolagus cuniculus) was presented for severe ulcerative stromal keratitis of the right eye and a luxated hypermature cataract and glaucoma of the left eye. Staged bilateral enucleation was elected. A LigaSure™ electrosurgical bipolar vessel-sealing device was used as a means to minimize intraoperative and post-operative hemorrhage, especially that associated with the orbital venous plexus. The LigaSure™ was used to ligate and transect all extraocular muscles, the optic nerve bundle, and the base of the third eyelid with no complications encountered. Overall, the LigaSure™ was easy to use, resulted in minimal hemorrhage, and reduced surgery time. This is the first report of the use of a LigaSure™ to aid in the enucleation of a rabbit. Although only positive results were achieved as an alternative to conventional methodologies, its use in clinical practice should be that of caution until a larger study evaluating the long-term results is performed.

Release Rates and Complications for Birds of Prey With Antebrachial Fractures at a Veterinary Teaching Hospital.

A retrospective case series that included 253 free-ranging birds of prey admitted to a rehabilitation center was conducted to describe the treatment and outcome of antebrachial fractures. Medical records from birds of prey belonging to 21 species admitted with antebrachial fracture between 1989 and 2015 at the University of California, Davis, were reviewed. Species distribution on admission, treatment, outcome, and complications were described by fracture category and species. Among 134 birds treated after initial triage on the day of admission, 4 bone/ wing categories were identified: 83 birds had an ulnar fracture only; 18 birds had a radial fracture only; 28 birds had a concomitant fracture of the radius and ulna on the same wing; and 5 birds had bilateral antebrachial fractures. Logistic regressions were performed to determine which factors were associated with a positive outcome within each of these 4 categories. Among birds having only an ulnar fracture, those with a closed fracture were significantly more likely to be released than birds with open fractures (P = .03; odds ratio = 5.43, 95% confidence interval: 1.29-28.12). In addition, birds with a fracture of the middle third of the ulna were significantly more likely to be released than birds diagnosed with a single fracture of the proximal third of the ulna (P = .02; odds ratio = 4.54, 95% confidence interval: 1.35-16.64). No significant prognostic factor was detected in other fracture categories.

Morphologic and quantitative evaluation of bone marrow aspirates from Hispaniolan Amazon parrots (Amazona ventralis).

BACKGROUND: Bone marrow aspirate assessments provide valuable information about hematopoietic status and hematologic disease. Hematopoietic cell differentials and morphologies have been anecdotally described in psittacines, but quantitative studies are lacking. OBJECTIVES: We aimed to determine differential cell counts and calculate granulocyte:erythroid (G:E) ratios in bone marrow aspirates from Hispaniolan Amazon parrots and report representative morphologies of the hematopoietic cells. METHODS: Bone marrow aspirates were collected from 32 clinically healthy, captive, parrots. Peripheral blood was obtained for CBCs. Bone marrow differential cell counts (%) were determined by counting 500 cells on modified Wright's-stained smears. G:E ratios were calculated. Representative images of hematopoietic cells at all stages of development were taken. RESULTS: Of the 32 parrots sampled, 17 bone marrow samples were of sufficient cellularity and quality for evaluation. Erythroid cells comprised 68.9 ± 8.6% (total ± SD) of the hematopoietic cells and consisted primarily of early- and late-stage polychromatophilic rubricytes (43.6 ± 2.1% of total erythroid cells). Granulocytic cells comprised 28.1 ± 3.8% of the hematopoietic cells and consisted primarily of mature and band heterophils (11.9 ± 5.2% and 6.5 ± 3.4%, respectively, of total granulocytic cells). A unique morphologic finding in avian progranulocytes was the presence of multiple different granules. The G:E ratio was 0.4 ± 0.2 (median 0.4, range 0.1-0.9). Thrombocyte lineage cells could not be reliably identified and were not counted. CBC results were largely within expected limits. CONCLUSIONS: The low G:E ratios observed could be normal in this species; however, these ratios could be affected by factors related to sampling and cell identification. These findings will be a valuable resource for the diagnostic evaluation of clinical bone marrow samples from Hispaniolan Amazon parrots and could serve as a general reference for psittacine bone marrow evaluation.

Clinical and pathological findings for rabbits with dystocia: 10 cases (1996-2016).

OBJECTIVE: To characterize clinical and pathological findings of rabbits evaluated at a veterinary teaching hospital because of dystocia. DESIGN: Retrospective case series. ANIMALS: 9 client-owned rabbits and 1 wild rabbit with signs of dystocia evaluated at a veterinary teaching hospital from 1996 through 2016. PROCEDURES: Medical records of rabbits were reviewed to collect data on signalment; medical history; physical examination, laboratory, diagnostic imaging, and procedural findings; treatment; final diagnosis; and outcome. Data were summarized. RESULTS: Dystocia in 7 rabbits was successfully managed through medical treatment, assisted vaginal delivery, or both (n = 6) or surgery alone (1); 3 rabbits were euthanized. Primiparous does, does ≤ 4 years old, and does of small breeds (< 2 kg [4.4 lb]) were most common. All client-owned rabbits had clinical signs of abnormal second-stage parturition, whereas the wild rabbit had only hemorrhagic vulvar discharge. Imaging was used to identify the number, size, and state of fetuses in most rabbits. Overall, 35 fetuses were accounted for, 25 of which were dead or later died. The cause of dystocia was determined for 8 rabbits and included fetal-maternal mismatch (n = 4), uterine inertia (2), fetal death or mummification (1), and stress-induced abortion (1). CONCLUSIONS AND CLINICAL RELEVANCE: Obstructive dystocia from fetal macrosomia with or without secondary uterine inertia was the most common cause of dystocia in the evaluated rabbits. Although medical management was successful for many rabbits with dystocia in this study, surgery could still be required in other affected rabbits, particularly when fetal-maternal mismatch is involved.

Companion rats (Rattus norvegicus) with cutaneous lesions: a retrospective study of 470 cases at two university veterinary teaching hospitals (1985-2018).

BACKGROUND: Rats are popular companion animals that are often presented to veterinarians for treatment of skin diseases. However, descriptions of dermatoses in rats have primarily been limited to case reports and text books. HYPOTHESIS/OBJECTIVES: To document skin diseases and their prevalence in companion rats examined in northern California, USA and Nantes, France and to investigate predilections for the most common conditions over a 33 year or 15 year period, respectively. ANIMALS: Four hundred and seventy rats from two hospital populations met the inclusion criteria. METHODS AND MATERIALS: A retrospective study was performed by searching computerized medical records of rats seen at the School of Veterinary Medicine at University of California, Davis (UCD), USA from 1 January 1985 to 1 January 2018 using the key words "skin" and "dermatitis". The medical records of rats presenting to Ecole Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes-Atlantique (ONIRIS), France from 1995 to 2016 were reviewed for evidence of skin disease. The presence of lesions as noted in the key search words for the UCD records were used as the inclusion criteria for both institutions. RESULTS: Of 494 rats examined at UCD, 231 (47%) had skin disease, with neoplasia the most common diagnosis. Of the 619 rats examined at ONIRIS, 239 (39%) had skin disease, with ectoparasitism being the most common diagnosis. CONCLUSIONS AND CLINICAL IMPORTANCE: Cutaneous conditions in companion rats are common. Clinicians should include a dermatological examination when examining these rodents, especially in regard to neoplasia, ectoparasites and pyoderma.

Companion hamsters with cutaneous lesions; a retrospective study of 102 cases at two university veterinary teaching hospitals (1985-2018).

BACKGROUND: Hamsters are popular companion animals which may present to veterinarians for treatment of skin diseases. Most descriptions of dermatoses in hamsters have primarily been in case reports and in text books. HYPOTHESIS/OBJECTIVES: To document skin diseases and their prevalence in companion hamsters examined in northern California, USA, and Nantes, France, and to investigate predilections for the most common conditions documented in medical records over a 33 year or 15 year period, respectively. ANIMALS: One hundred and one hamsters from two hospital populations. METHODS AND MATERIAL: A computerized search of medical records of all hamsters seen at the School of Veterinary Medicine at UC-Davis in California, USA, from 1 January 1985 to 1 January 2018, was performed using the key search words "skin" and "dermatitis". The medical records of all hamsters presenting to the Ecole Nationale Vétérinaire, Nantes, from 1 September 1998 to 1 December 2013, were reviewed for skin diseases. The presence of lesions noted in key search words for the California records were used as inclusion guidelines for both institutions. Cases of suspected mammary neoplasia were excluded. RESULTS: Of the 65 hamsters seen in California, 34 (54%) had skin disease; of a total of 164 hamsters in Nantes, 67 (41%) had skin disease. Nodules were the most common lesions noted by both institutions. CONCLUSIONS AND CLINICAL IMPORTANCE: Cutaneous conditions in companion hamsters are common. Clinicians should include a dermatological examination when examining these rodents.

A novel herpesvirus associated with chronic superficial keratitis and proliferative conjunctivitis in a great horned owl (Bubo virginianus).

An adult great-horned owl (Bubo virginianus; GHOW) presented with a history of recurrent corneal ulceration of the right eye (OD). Findings included ulcerative superficial keratitis, proliferative conjunctivitis, and iris pigmentary changes. The ulcer was initially nonresponsive to medical therapy, but showed rapid and appropriate healing following diamond burr debridement. Proliferative conjunctivitis markedly improved following topical antiviral therapy with cidofovir 1%, interferon alpha 2B ophthalmic solutions, and oral l-lysine. Histopathologic evaluation of a conjunctival biopsy revealed epithelial features suspicious for viral cytopathic changes and intranuclear structures suspicious for viral inclusions, suggestive of a possible viral-induced papillomatous conjunctivitis. A novel alphaherpesvirus, referred to as Strigid Herpesvirus 1 (StrHV1), was identified using PCR and gene sequencing. This case represents a new clinical manifestation of a previously unreported herpesvirus in the GHOW. Identification of the herpes virus was critical to administration of appropriate therapy and resolution of the conjunctivitis, and corneal epithelial debridement promoted resolution of the chronic corneal epithelial defect.

Evaluation of the Thermal Antinociceptive Effects of a Sustained-Release Buprenorphine Formulation After Intramuscular Administration to American kestrels ( Falco sparverius).

Previous studies have validated the clinical use of opioids with µ-receptor affinities for pain management in raptors. Buprenorphine has a longer duration of action and minimal adverse effects when compared with other opioids in American kestrels ( Falco sparverius). To evaluate the thermal antinociceptive effects, sedative effects, and duration of action of sustained-release buprenorphine given intramusculary in American kestrels, 12 adult kestrels (8 females and 4 males) were used in a randomized masked complete-crossover experimental design. Buprenorphine SR LAB (1.8 mg/kg) or a control solution were administered intramuscularly. Foot withdrawal response to a thermal stimulus was determined 1 hour before (baseline) and at 1.5, 6, 12, 24, 48, and 72 hours after treatment administration. Agitation-sedation scores were determined 3-5 minutes before each time point, and adverse effects were monitored at these times. Buprenorphine SR LAB significantly increased thermal thresholds at 6, 12, and 24 hours and resulted in mild sedation according to the mean sedation-agitation scores comparing the treatment and control groups. Depending on the severity and type of pain, adjunctive therapy, and individual response, Buprenorphine SR LAB administered at 1.8 mg/kg IM to American kestrels would require administration every 24 hours to manage pain. Further pharmacodynamic and clinical evaluations are warranted in kestrels and other Falconiformes, Accipitriformes, and Strigiformes to establish accurate dosing recommendations.

Clinical features, treatment, and outcomes of cutaneous and oral squamous cell carcinoma in avian species.

OBJECTIVE To determine the clinical features, treatment, and outcomes of treatment for oral and cutaneous squamous cell carcinoma (SCC) in avian species. DESIGN Retrospective case series with nested cohort study. ANIMALS 87 client-owned birds of various species with histologically confirmed SCC of the skin or oral cavity. PROCEDURES Clinicians entered case information through an online survey tool. Data were collected regarding patient signalment, concurrent conditions, treatments, adverse effects, and clinical outcomes. Relationships were examined between complete excision and partial or complete response. Survival analysis was performed to compare outcomes among groupings of therapeutic approaches. RESULTS Only 7 of 64 (11%) birds for which full outcome data were available had complete remission of SCC; 53 (83%) had progressive disease, were euthanized, or died of the disease. The unadjusted OR for partial or complete response following complete tumor excision (vs other treatment approaches) was 6.9 (95% confidence interval [CI], 1.8 to 25.8). Risk of death was 62% lower (hazard ratio, 0.38; 95% CI, 0.19 to 0.77) for birds that underwent complete excision versus conservative treatment. Median survival time from initial evaluation for birds receiving complete excision was 628 days (95% CI, 210 to 1,008 days), compared with 171 days (95% CI, 89 to 286 days) for birds receiving monitoring with or without conservative treatment. Birds receiving any other additional treatment had a median survival time of 357 days (95% CI, 143 to 562 days). CONCLUSIONS AND CLINICAL RELEVANCE For birds with SCC, complete excision was the only treatment approach significantly associated with complete or partial response and increased survival time.

Pharmacokinetics of a Sustained-release Formulation of Meloxicam After Subcutaneous Administration to Hispaniolan Amazon Parrots (Amazona ventralis).

Meloxicam has been shown to have a safe and favorable pharmacodynamic profile with individual variability in Hispaniolan Amazon parrots (Amazona ventralis). In the current study, we determined the pharmacokinetics of a sustained-release formulation of meloxicam after subcutaneous administration to Hispaniolan Amazon parrots. Twelve healthy adult parrots, 6 males and 6 females, were used in the study. Blood samples were collected before (time 0) and at 0.5, 1, 2, 6, 12, 24, 48, 72, 96, and 120 hours after a single dose of the sustained-release meloxicam formulation (3 mg/kg SC). Plasma meloxicam concentrations were measured by high-pressure liquid chromatography. Pharmacokinetic parameters were determined by noncompartmental analysis. Plasma concentrations reached a mean Cmax of 23.4 µg/mL (range, 14.7-46.0 µg/mL) at 1.8 hours (range, 0.5-6 hours), with a terminal half-life of 7.4 hours (range, 1.4-40.9 hours). Individual variation was noticeable, such that some parrots (4 of 12 birds) had very low plasma meloxicam concentrations, similar to the high variability reported in a previous pharmacokinetic study of the standard meloxicam formulation in the same group of birds. Two birds developed small self-resolving scabs at the injection site. On the basis of these results, the sustained-release meloxicam formulation could be administered every 12 to 96 hours in Hispaniolan Amazon parrots to manage pain. Because of these highly variable results, the use of this formulation in this species cannot be recommended until further pharmacokinetic, safety, and pharmacogenomic evaluations are performed to establish accurate dosing recommendations and to understand the high pharmacokinetic variability.

Pharmacokinetics of a Sustained Release Formulation of Buprenorphine After Intramuscular and Subcutaneous Administration to American Kestrels ( Falco sparverius ).

Previous studies have validated the clinical use of opioids with µ-receptor affinities for pain management in raptors. Buprenorphine appears to have a longer duration of action and minimal adverse effects when compared to other opioids in American kestrels ( Falco sparverius ). To determine the pharmacokinetics of a sustained release formulation of buprenorphine in kestrels, we administered a commercially available product (Buprenorphine SR-LAB; Wildlife Pharmaceuticals, Windsor, CO, USA) intramuscularly and subcutaneously to adult kestrels in a partial-crossover experimental design study. A total of 12 birds (6 males and 6 females) were assigned randomly to 3 groups of 4 birds each. A single dose of Buprenorphine SR-LAB (1.8 mg/kg) was administered intramuscularly (IM), and blood samples were collected at 0.25, 3, and 24 hours (n = 4); 1, 6, and 48 hours (n = 4); and 2, 12, and 72 hours (n = 4) after drug administration. Plasma buprenorphine concentrations were measured by tandem liquid chromatography-mass spectrometry. Pharmacokinetic parameters were determined by use of least squares linear regression and noncompartmental analysis of naïve pooled data. After 1 year, the same dose of buprenorphine was administered subcutaneously (SC) to 12 birds divided into 3 groups as previously, and blood samples were collected at the same times after drug administration. Maximum plasma buprenorphine concentration was measured at 15 minutes after IM and SC administration. Mean plasma buprenorphine concentrations were >1 ng/mL for 48 hours after IM and SC administration. The elimination half-life was 13.5 and 11.1 hours for IM and SC administration, respectively. Depending on the severity and type of pain, adjunctive therapy, and the individual response, Buprenorphine SR-LAB administered at 1.8 mg/kg IM or SC to American kestrels would require administration every 12 to 72 hours to manage pain. Further pharmacodynamic and clinical evaluations are warranted in kestrels and other raptors to establish accurate dosing recommendations.