Search

OBJECTIVE To determine the pharmacokinetic parameters of hydromorphone hydrochloride and its metabolite, hydromorphone-3-glucuronide (H3G), after a single IV and IM dose in great horned owls (Bubo virginianus). ANIMALS 6 healthy adult great horned owls (3 females and 3 males). PROCEDURES A single dose of hydromorphone (0.6 mg/kg) was administered once IM (pectoral muscles) and IV (left jugular) with a 6-week washout period between experiments. Blood samples were collected at 5 minutes and 0.5, 1.5, 2, 3, 6, 9, and 12 hours after drug administration. Plasma hydromorphone and H3G concentrations were determined with liquid chromatography–tandem mass spectrometry, and a noncompartmental analysis was used for the determination of pharmacokinetic parameters. RESULTS Hydromorphone had a high bioavailability of 170.8 ± 37.6% and rapid elimination after IM administration and rapid plasma clearance and a large volume of distribution after IV administration. Mean Cmax was 225.46 ± 0.2 ng/mL at 13 minutes after IM injection. Mean volume of distribution and plasma drug clearance was 4.29 ± 0.5 L/kg and 62.11 ± 14.6 mL/min/kg, respectively, after IV administration. Mean t1/2 was 1.62 ± 0.36 and 1.35 ± 0.59 hours after IM and IV administration, respectively. The metabolite H3G was readily measured shortly after administration by both routes. CLINICAL RELEVANCE A single dose of 0.6 mg/kg was well tolerated in all birds. Hydromorphone rapidly attained plasma concentrations following IM administration and had high bioavailability and short t1/2. This study is the first to document the presence of the metabolite H3G in avian species, which suggests similar hydromorphone metabolism as in mammals.

OBJECTIVE To determine the pharmacokinetics of 8 cannabinoids and 5 metabolites after oral administration of single and multiple doses of a cannabidiol (CBD)-cannabidiolic acid (CBDA)–rich hemp extract to orange-winged Amazon parrots (Amazona amazonica) as well as to evaluate the extract’s adverse effects. ANIMALS 12 birds. PROCEDURES Based on pilot studies, a single-dose study based on 30/32.5 mg/kg of cannabidiol/cannabidiolic acid of a hemp extract was administered orally to 8 fasted parrots, and 10 blood samples were collected over 24 hours after administration. After a 4-week washout period, the hemp extract was administered orally to 7 birds at the previous dose every 12 hours for 7 days, and blood samples were collected at the previous time points. Cannabidiol, Δ9-tetrahydrocannabinol, cannabinol, cannabichromene, cannabigerol, cannabidiolic acid, cannabigerolic acid, Δ9-tetrahydrocannabinolic acid, and 5 specific metabolites were measured by liquid chromatography-tandem/mass-spectrometry, and pharmacokinetic parameters were calculated. Adverse effects and changes in the plasma biochemistry and lipid panels were evaluated. RESULTS Pharmacokinetic parameters for cannabidiol, cannabidiolic acid, Δ9-tetrahydrocannabinol, Δ9-tetrahydrocannabinolic acid, and the metabolite 11-hydroxy-9-tetrahydrocannabinol were established. For the multiple-dose study, cannabidiol/cannabidiolic acid mean Cmax was 337.4/602.1 ng/mL with a tmax of 30 minutes and a terminal half-life of 8.6/6.29 hours, respectively. No adverse effects were detected during the multidose study. The predominant metabolite was 11-hydroxy-9-tetrahydrocannabinol. CLINICAL RELEVANCE Twice daily oral administration of the hemp extract based on 30 mg/kg/32.5 mg/kg of cannabidiol/cannabidiolic acid was well tolerated and maintained plasma concentrations considered to be therapeutic in dogs with osteoarthritis. Findings suggest different cannabinoid metabolism from mammals.

The recognition and assessment of pain in avian species are crucial tools in providing adequate supportive care in clinical, laboratory, zoologic, rehabilitation, and companion animal settings. With birds being a highly diverse class of species, there is still much to be determined regarding how to create specific criteria to recognize and assess pain in these animals. This article provides a clinical review on the physiology of pain in birds, observed behavioral and physiologic alterations with pain, how different sources and degrees of pain can alter behaviors observed, and how this information can be applied in a clinical setting.

This article provides an overview of the current understanding of evidence-based clinical analgesic use in birds. The field of avian analgesia has dramatically expanded during the last 20 years, affording more options for alleviating both acute and chronic pain. These options include opioids, nonsteroidal anti-inflammatory drugs, local anesthetics, and/or other drugs like gabapentin, amantadine, and cannabinoids, acting at different points in the nociceptive system thereby helping to provide greater pain relief while reducing the risk of adverse effects when combined.

Rabbits occupy facets of veterinary medicine spanning from companion mammals, wildlife medicine, zoologic species, and research models. Therefore, analgesia is required for a variety of conditions in rabbits and is a critical component of patient care. Considerations when selecting an analgesic protocol in rabbits include timing of administration, route of administration, degree or anticipated pain, ability to access or use controlled drugs, systemic health, and any potential side effects. This review focuses on pharmacologic and locoregional management of pain in rabbits and emphasizes the need for further studies on pain management in this species.

OBJECTIVE To document clinicopathologic findings in domestic rabbits with liver lobe torsion and identify prognostic factors. ANIMALS 82 rabbits. PROCEDURE Medical records of 4 institutions were reviewed to identify rabbits with an antemortem diagnosis of liver lobe torsion that were examined between 2010 and 2020. RESULTS The prevalence of liver lobe torsion was 0.7% (82/11,402). In all 82 rabbits, the diagnosis was made by means of abdominal ultrasonography. Fifty (60.1%) rabbits underwent liver lobectomy, 23 (28%) received medical treatment alone, and 9 (10.9%) were euthanized or died on presentation. Overall, 32 (39%) rabbits died within 7 days of initial presentation and 50 (61%) survived. Seven-day survival rate did not differ significantly between medical treatment alone and surgical treatment. However, median survival time following medical treatment (530 days) was shorter than that following surgical treatment (1,452 days). Six of 14 rabbits had evidence of systemic inflammatory disease on necropsy. Rabbits with right liver lobe torsion were less likely to survive for 7 days than were those with caudate torsions (P = 0.046; OR, 3.27; 95% CI, 1.04 to 11.3). Rabbits with moderate to severe anemia were less likely to survive for 7 days than were rabbits that were not anemic or had mild anemia (P = 0.006; OR, 4.41; 95% CI, 1.55 to 12.51). Other factors associated with a decreased 7-day survival rate were high heart rate at admission (P = 0.013) and additional days without defecation after admission (P < 0.001). Use of tramadol was associated with an increased survival rate (P = 0.018). CLINICAL RELEVANCE The prognosis for rabbits with liver lobe torsions was more guarded than previously described. Rabbits that underwent liver lobectomy had a longer median survival time than did rabbits that only received medical treatment.

OBJECTIVE To document the clinical signs, diagnosis, and treatment of urolithiasis in green iguanas (Iguana iguana) and to report on the composition of uroliths from green iguanas submitted to the Minnesota Urolith Center for analysis. ANIMALS 21 green iguanas with urolithiasis. PROCEDURES Medical record databases of multiple veterinary teaching hospitals were searched from 1996 through 2020. Emails were sent to all facilities that submitted a urolith from a green iguana to the Minnesota Urolith Center from 1996 through 2020. Signalment; presenting complaint; physical examination findings; hematologic, biochemical, and diagnostic imaging findings; treatment; necropsy results; and survival times were described for each patient. RESULTS Iguanas most commonly presented with nonspecific clinical signs, but 9 of the 21 iguanas had clinical signs associated with the urogenital tract. Twelve iguanas had a palpable mass in the caudal coelom. All uroliths were visible on radiographs. Surgery was performed on 15 iguanas; 3 died secondary to intra- or postoperative complications. Iguanas that underwent surgery had a median survival time of 39 months. Necropsy was performed on 5 iguanas, and urolithiasis contributed to the decision to euthanize or was the cause of death for 4. Uroliths from 132 iguanas were analyzed, and all were composed of 100% uric acid salts. CLINICAL RELEVANCE Green iguanas with urolithiasis may not have clinical signs or physical examination findings associated with the urinary system, and hematologic and biochemical abnormalities are nonspecific. Green iguanas should be routinely examined for uroliths, and surgical treatment should be pursued.

OBJECTIVE To determine the pharmacokinetics and potential adverse effects of pimobendan after oral administration in New Zealand White rabbits (Ocytolagus cuniculi). ANIMALS 10 adult sexually intact (5 males and 5 females) rabbits. PROCEDURES 2 pilot studies were performed with a pimobendan suspension or oral tablets. Eight rabbits received 7.5 mg of pimobendan (mean 2.08 mg/kg) suspended in a critical care feeding formula. Plasma concentrations of pimobendan and O-demethylpimobendan (ODMP) were measured, and pharmacokinetic parameters were calculated for pimobendan by noncompartmental analysis. Body weight, food and water consumption, mentation, urine, and fecal output were monitored. RESULTS Mean ± SD maximum concentration following pimobendan administration was 15.7 ± 7.54 ng/mL and was detected at 2.79 ± 1.25 hours. The half-life was 3.54 ± 1.32 hours. Plasma concentrations of pimobendan were detectable for up to 24 hours. The active metabolite, ODMP, was detected in rabbits for 24 to 36 hours. An adverse event occurred following administration of pimobendan in tablet form in 1 pilot study, resulting in death secondary to aspiration. No other adverse events occurred. CLINICAL RELEVANCE Plasma concentrations of pimobendan were lower than previously reported for dogs and cats, despite administration of higher doses, and had longer time to maximum concentration and half-life. Based on this study, 2 mg/kg of pimobendan in a critical care feeding formulation should maintain above a target plasma concentration for 12 to 24 hours. However, further studies evaluating multiple-dose administration as well as pharmacodynamic studies and clinical trials in rabbits with congestive heart failure are needed to determine accurate dose and frequency recommendations.

OBJECTIVE To determine the clinical and pathological findings of rabbits diagnosed with lymphoma. ANIMALS 16 rabbits. PROCEDURES The medical and pathology records database of the Veterinary Medical Teaching Hospital at the University of California, Davis was searched for rabbits diagnosed with lymphoma from 1996 to 2019. RESULTS Mean age of the 16 rabbits was 8 years (range, 4.5 to 12 years). Immunophenotyping was performed in 14 cases. Diffuse, large, B-cell lymphoma was most common (n = 7) followed by epitheliotropic, T-cell lymphoma (2); type II enteropathy-associated, T-cell lymphoma (2); marginal-zone, B-cell lymphoma (1); peripheral, T-cell lymphoma not otherwise specified (cutaneous nonepitheliotropic lymphoma; 1); primary, mediastinal (thymic) large B-cell lymphoma (1), and unclassified (cytology only with no immunophenotyping; 2). Multiple chemotherapy protocols were used on the basis of each individual animal’s disease state. Initial clinical improvement was reported for most rabbits receiving chemotherapy (5/6), with diffuse B-cell lymphoma responding most favorably to treatment. The 11 rabbits included in the survival analysis had a median survival time of 60 days (range, 1 to 480 days), and those diagnosed with B- and T-cell lymphoma had a median survival time of 8 and 36 days (range, 1 to 150 and 1 to 90 days), respectively. CLINICAL RELEVANCE Rabbits develop a range of lymphoma subtypes and, similar to humans and dogs, diffuse large B-cell lymphoma appears to be the most common. Chemotherapy treatments followed multiple protocols, which were mostly well tolerated and had a highly variable response. Further research into chemotherapy protocols is needed to optimize treatment of lymphoma in rabbits.

Although cockatiels are among the most common avian species maintained as companion animals in the United States, information on standard hematologic reference values for this species is limited. The objectives of this study were to establish hematologic reference intervals (RI) for cockatiels, compare methods using both the Natt-Herrick technique (NHT) and the smear-based estimation technique (SBT), explore age and sex differences in the hematologic findings for this species, and produce the first cockatiel RI for fibrinogen concentration and thrombocyte estimate. Healthy cockatiels (60 males and 60 females, 2-11 years old) from a research colony were included in this study. Blood samples were placed in dipotassium ethylenediaminetetraacetic acid tubes, and erythrocyte counts and thrombocyte estimates were determined via automated analyzer (ADVIA 120) and SBT, respectively. Moreover, leukocyte concentrations were determined using both NHT and SBT to compare these common methods for measuring a complete blood count in cockatiels. Data were analyzed for outliers, distributions, descriptive statistics, and RI via Reference Value Adviser, a set of macroinstructions for Microsoft Excel (Microsoft, Redmond, WA, USA). Lymphocytes were the predominant leukocyte across both methods. According to the NHT, females had significantly higher concentrations of total leukocytes, heterophils, bands, lymphocytes, basophils, and total plasma protein compared with males. Significant inverse polynomial relationships were noted between total leukocyte count and age and lymphocyte counts and age for NHT. Total leukocyte count produced via NHT and SBT were compared using Passing-Bablok and Bland-Altman plots, and no significant constant or proportional biases were found. However, these methods showed wide limits of agreement. While the RI were interchangeable between methods from a clinical standpoint, the same method should be used to assess changes in an individual. The reported RI are uniquely robust given the sample size, balanced sex and age distributions, inclusion criteria, and control over sample collection.

OBJECTIVE To determine epidemiological features of cardiovascular disease in rabbits examined at a veterinary teaching hospital and characterize clinical and pathological findings. ANIMALS 59 rabbits. PROCEDURES Medical records from 2001 to 2018 were reviewed, and data were collected. Echocardiographic images and histologic diagnoses were reviewed. RESULTS The prevalence of cardiovascular disease was 2.6% (59/2,249). Clinical signs related to cardiac disease included heart murmur (n = 25 rabbits), arrhythmia (22), tachypnea or dyspnea (13), hyporexia or anorexia (13), and muscle wasting (9). Radiographic (n = 39) abnormalities included cardiomegaly (19) and peritoneal (12) and pleural (11) effusion. Common echocardiographic (n = 37) diagnoses included degenerative valve disease (15), dilated cardiomyopathy (7), unclassified cardiomyopathy (4), restrictive cardiomyopathy (3), and hypertrophic cardiomyopathy (2). On ECG (n = 19), supraventricular arrhythmias (16) were more common than ventricular arrhythmias (12). Thirty-five necropsy reports were available, and diagnoses included cardiomyopathy (n = 14), myocarditis (10), and arteriosclerosis (9). Medical management (n = 20) included a wide range of drugs and dosages with few adverse effects. Survival times (n = 36 rabbits) ranged from 1 to 2,353 days with a median cardiac disease–specific survival time of 306 days. CONCLUSIONS AND CLINICAL RELEVANCE The findings provided information on the prevalence of cardiovascular disease in rabbits and survival times for affected rabbits. Right-sided, left-sided, and biventricular congestive heart failure occurred equally. Median survival time was lower than that reported for other species. Further research on the diagnosis and treatment of cardiovascular disease in rabbits is needed.

Background In the US, the median age of adults experiencing homelessness and incarceration is increasing. Little is known about risk factors for incarceration among older adults experiencing homelessness. To develop targeted interventions, there is a need to understand their risk factors for incarceration. Objective To examine the prevalence and risk factors associated with incarceration in a cohort of older adults experiencing homelessness. Design Prospective, longitudinal cohort study with interviews every 6 months for a median of 5.8 years. Participants We recruited adults ≥50 years old and homeless at baseline (n=433) via population-based sampling. Main Measures Our dependent variable was incident incarceration, defined as one night in jail or prison per 6-month follow-up period after study enrollment. Independent variables included socioeconomic status, social, health, housing, and prior criminal justice involvement. Key Results Participants had a median age of 58 years and were predominantly men (75%) and Black (80%). Seventy percent had at least one chronic medical condition, 12% reported heavy drinking, and 38% endorsed moderate-severe use of cocaine, 8% of amphetamines, and 7% of opioids. At baseline, 84% reported a lifetime history of jail stays; 37% reported prior prison stays. During follow-up, 23% spent time in jail or prison. In multivariable models, factors associated with a higher risk of incarceration included the following: having 6 or more confidants (HR=2.13, 95% CI=1.2–3.7, p=0.007), remaining homeless (HR=1.72, 95% CI=1.1–2.8, p=0.02), heavy drinking (HR=2.05, 95% CI=1.4–3.0, p

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 (

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 (

OBJECTIVES To determine the pharmacokinetics of butorphanol tartrate incorporated into poloxamer 407 (P407) after subcutaneous administration to orange-winged Amazon parrots (Amazona amazonica). ANIMALS Six orange-winged Amazon parrots, ages 28 to 45 years. PROCEDURES A sterile formulation of butorphanol in P407 (But-P407) as a 25% gel was created to produce a concentration of 8.3 mg/mL. The formulation was administered SC at a dose of 12.5 mg/kg to all birds. Blood samples were collected at baseline prior to injection (time 0) and then at 0.08, 0.5, 1, 1.5, 4, 8, and 12 hours after drug administration. Butorphanol concentrations were quantitated via liquid chromatography–tandem mass spectrometry. Pharmacokinetic analysis was performed using noncompartmental analysis and a commercially available software program. RESULTS Plasma concentrations of butorphanol remained > 100 ng/mL for > 4 hours for some birds (3/5) but were < 100 ng/mL for all birds by the 8-hour mark. Cmax and tmax were 346.9 ± 233.7 ng/mL and 1.3 ± 0.274 hours, respectively. Half-life was 1.56 ± 0.445 hours. No adverse effects were detected. CLINICAL RELEVANCE Butorphanol was absorbed from the But-P407 25% by the majority of the orange-winged Amazon parrots in this study (3/5), although to a lesser extent compared to Hispaniolan Amazon parrots. Absorption followed a pharmacokinetic profile compatible with a sustained-release drug. A dose of 12.5 mg/kg, SC, would be expected to provide antinociception for 4 to 8 hours, although pharmacodynamic studies in this species using this formulation have not demonstrated this.

OBJECTIVES To evaluate a carrageenan-induced inflammatory model in the cockatiel (Nymphicus hollandicus) using weight-bearing load, rotational perch locomotion, thermal threshold withdrawal, and footpad dimensions. ANIMALS 16 adult cockatiels (8 males and 8 females). PROCEDURES Cockatiels were randomly assigned into 2 groups as either treatment (carrageenan injection; n = 8) or control (handling only; 8). Treatment of cockatiels involved unilateral subcutaneous injection of 0.05 mL of 1% lambda carrageenan solution into the left footpad. Control birds were handled in a similar manner without an injection. Following baseline measurements and treatment or control procedures, posttreatment measurements at multiple time points involving weight-bearing perch load (for up to 336 hours), locomotive abilities when placed on a rotating perch (for up to 96 hours), thermal withdrawal threshold (for the 24- to 30-hour period), and both vertical and horizontal left footpad size and degree of swelling (for up to 84 days) were obtained. RESULTS Treatment cockatiels had a significant decrease in left foot weight-bearing load and increase in left footpad dimensions and swelling grade over time compared to control cockatiels. Rotational perch locomotion and thermal withdrawal threshold, conversely, did not differ significantly between groups. Cockatiels injected with carrageenan returned to normal weight-bearing within 2 weeks; however, left footpad dimensions did not return to baseline. CLINICAL RELEVANCE Carrageenan footpad injection prompts a measurable and grossly visible inflammatory response in the cockatiel. Additionally, it induces alterations in weight-bearing distribution in injected birds. This model provides a method to evaluate inflammation and lameness in small psittacine species.

Maropitant citrate is a synthetic neurokinin-1 receptor antagonist and substance P inhibitor used for control of emesis in dogs in cats. Maropitant citrate is used empirically in birds, despite a lack of pharmacokinetic data in avian species. The objective of this study was to determine the pharmacokinetic profile of a single dose of maropitant citrate 1 and 2 mg/kg subcutaneously (SC) in eight Rhode Island Red hens (Gallus gallus domesticus). A crossover study design was used with 1-week washout between trials. Blood samples were collected over 36 h after drug administration. Plasma concentrations were measured using liquid chromatography-tandem mass spectrometry and pharmacokinetic parameters were determined via non-compartmental analysis. The mean maximum plasma concentration, time to maximum concentration, and elimination half-life following 1 and 2 mg/kg SC were 915.6 ± 312.8 ng/ml and 1195.2 ± 320.2 ng/ml, 0.49 ± 0.21 h and 1.6 ± 2.6 h, and 8.47 ± 2.24 h and 8.58 ± 2.6 h, respectively. Pharmacokinetic data suggests doses of 1 or 2 mg/kg SC may be administered every 12-24 h to maintain above target plasma concentration similar to dogs (90 ng/ml). These data provide a basis for further investigation of maropitant citrate pharmacokinetics and pharmacodynamics in birds.

This prospective study evaluated oral transmucosal pentobarbital sodium at three doses in 110 wild-caught wild birds requiring euthanasia. Birds received transmucosal pentobarbital at five (430 mg/kg), six (516 mg/kg), and seven times (602 mg/kg) the intravenous dose for mammals. Time to first effects and loss of consciousness, presence of pupillary light and corneal reflexes, apnea, and asystole were recorded each minute. When asystole was not achieved at 5 minutes, IV pentobarbital was administered. Combining data for all doses, loss of consciousness occurred at a median (range) of 2 minutes (0-4.75 min), apnea at 3 minutes (0-6 min), and asystole at 4 minutes (0.5-5 min). Loss of consciousness and apnea occurred significantly faster in the 602 mg/kg dose group than in the 430 mg/kg group (p = 0.009, difference of 0.6 ± 0.2 min; p = 0.024, difference of 0.7 ± 0.3 min), respectively. Apnea and asystole were achieved in 80/110 birds within 5 minutes. Oral transmucosal pentobarbital results in rapid loss of consciousness and respiratory arrest and provides a reliable alternative euthanasia method compared to intravenous administration.

Envenomation in avian species can result in death, with few cases of successful treatment described. A juvenile, wild-caught, intact female red-tailed hawk (

OBJECTIVE To evaluate neurological tests and expected results in inland bearded dragons (Pogona vitticeps) and generate recommendations for bearded dragon–specific neurological examination. ANIMALS 26 healthy adult inland bearded dragons. PROCEDURES A complete neurological examination utilizing tests described in both mammals and reptiles was performed on each lizard, and test feasibility and outcome were recorded. RESULTS Tests with poor feasibility included oculocardiac reflex (successfully completed in 62% [16/26] of animals) and voluntary ambulation and swallowing by use of a food item (0% [0/26] of animals). Tests with outcomes considered abnormal in mammals but attributable to normal bearded dragon behavior included head position (head tilt present in 12% [3/26]) and head movement (head bob present in 4% [1/26]). Many tests had absent or inconsistent outcomes, including menace response (present in 19% [5/26]), proprioceptive positioning (present in 4% [1/26] in the thoracic limbs and 0% [0/26] in the pelvic limbs), vent reflex (present in 27% [7/26]), and myotatic reflexes (biceps present in 8% [2/26]; patellar, gastrocnemius, and triceps present in 0% [0/26]). Extensor postural thrust was absent in all successfully tested animals, but a novel reflex termed the caudal thoracic extensor reflex was noted instead in all observed animals (100% [21/21]). CLINICAL RELEVANCE Tests with poor feasibility or inconsistent outcomes should have low priority or be excluded from neurological examinations of inland bearded dragons. Normal behaviors should be considered for head position and movement. A bearded dragon–specific neurological examination protocol derived from these findings is described and recommended in order to decrease stress and improve neurolocalization.

OBJECTIVE To evaluate the pharmacokinetics of hydromorphone hydrochloride after IM and IV administration to orange-winged Amazon parrots (Amazona amazonica). ANIMALS 8 orange-winged Amazon parrots (4 males and 4 females). PROCEDURES Hydromorphone (1 mg/kg) was administered once IM. Blood samples were collected 5 minutes and 0.5, 1.5, 2, 3, 6, and 9 hours after drug administration. Plasma hydromorphone concentrations were determined with liquid chromatography-tandem mass spectrometry, and pharmacokinetic parameters were calculated with a compartmental model. The experiment was repeated 1 month later with the same dose of hydromorphone administered IV. RESULTS Plasma hydromorphone concentrations were > 1 ng/mL for 6 hours in 8 of 8 and 6 of 7 parrots after IM and IV injection, respectively. After IM administration, mean bioavailability was 97.6%, and mean maximum plasma concentration was 179.1 ng/mL 17 minutes after injection. Mean volume of distribution and plasma drug clearance were 4.24 L/kg and 64.2 mL/min/kg, respectively, after IV administration. Mean elimination half-lives were 1.74 and 1.45 hours after IM and IV administration, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Hydromorphone hydrochloride had high bioavailability and rapid elimination after IM administration, with rapid plasma clearance and a large volume of distribution after IV administration in orange-winged Amazon parrots. Drug elimination half-lives were short. Further pharmacokinetic studies of hydromorphone and its metabolites, including investigation of multiple doses, different routes of administration, and sustained-release formulations, are recommended.

OBJECTIVE To evaluate the thermal antinociceptive effects of hydromorphone hydrochloride after IM administration to orange-winged Amazon parrots (Amazona amazonica). ANIMALS 8 healthy adult parrots (4 males and 4 females). PROCEDURES In a randomized crossover study, each bird received hydromorphone (0.1, 1, and 2 mg/kg) and saline (0.9% NaCl) solution (1 mL/kg; control) IM, with a 7-day interval between treatments. Each bird was assigned an agitation-sedation score, and the thermal foot withdrawal threshold (TFWT) was measured at predetermined times before and after treatment administration. Adverse effects were also monitored. The TFWT, agitation-sedation score, and proportion of birds that developed adverse effects were compared among treatments over time. RESULTS Compared with the mean TFWT for the control treatment, the mean TFWT was significantly increased at 0.5, 1.5, and 3 hours and 1.5, 3, and 6 hours after administration of the 1- and 2-mg/kg hydromorphone doses, respectively. Significant agitation was observed at 0.5, 1.5, and 3 hours after administration of the 1 - and 2-mg/kg hydromorphone doses. Other adverse effects observed after administration of the 1- and 2-mg/kg doses included miosis, ataxia, and nausea-like behavior (opening the beak and moving the tongue back and forth). CONCLUSIONS AND CLINICAL RELEVANCE Although the 1- and 2-mg/kg hydromorphone doses appeared to have antinociceptive effects, they also caused agitation, signs of nausea, and ataxia. Further research is necessary to evaluate administration of lower doses of hydromorphone and other types of stimulation to better elucidate the analgesic and adverse effects of the drug in psittacine species.

OBJECTIVE To characterize the CT findings and epidemiological features of acquired dental disease in rabbits. ANIMALS 100 client-owned rabbits (Oryctolagus cuniculus). PROCEDURES Medical records were searched to identify rabbits that underwent skull CT for any reason from 2009 to 2017. History, signalment, and physical examination findings were recorded. The CT images were reevaluated retrospectively for evidence of dental disease and graded according to a previously described system (from 1 [no evidence of disease] to 5 [severe dental disease]) for acquired dental disease in rabbits, and an overall (mean) grade was assigned. Descriptive analyses were performed. Factors were assessed for associations between dental disease grade and malocclusion stage. RESULTS Common findings included premolar or molar tooth curvature in transverse (n = 100 rabbits) and sagittal (95) planes, apical elongation of premolar or molar teeth (99), sharp dental points (93), deformation of the mandibular canal (82), and periodontal ligament space widening (76). Acquired dental disease was classified as grade 1 (n = 2 rabbits), 2 (60), 3 (14), 4 (4), or 5 (20). Most CT findings were significantly correlated with each other. Agreement of grades was fair between left- and right-sided quadrants and between maxillary and mandibular quadrants. Age was associated with increasing dental disease grade and malocclusion stage (proportional ORs, 1.21 and 1.32/y, respectively). CONCLUSIONS AND CLINICAL RELEVANCE Fair agreement in disease grades between dental quadrant pairs indicated a degree of asynchrony in the development of dental disease. Findings suggested premolar or molar tooth curvature in a sagittal plane, subtle elongation at premolar or molar tooth apices, and mandibular canal deformation should be added to the grading system.

OBJECTIVE To determine the pharmacokinetics of amantadine after oral administration of single and multiple doses to orange-winged Amazon parrots (Amazona amazonica). ANIMALS 12 adult orange-winged Amazon parrots (6 males and 6 females). PROCEDURES A single dose of amantadine was orally administered to 6 birds at 5 mg/kg (n = 2), 10 mg/kg (2), and 20 mg/kg (2) in a preliminary trial. On the basis of the results, a single dose of amantadine (10 mg/kg, PO) was administered to 6 other birds. Two months later, multiple doses of amantadine (5 mg/kg, PO, q 24 h for 7 days) were administered to 8 birds. Heart rate, respiratory rate, behavior, and urofeces were monitored. Plasma concentrations of amantadine were measured via tandem liquid chromatography–mass spectrometry. Pharmacokinetic parameter estimates were determined via noncompartmental analysis. RESULTS Mean ± SD maximum plasma concentration, time to maximum plasma concentration, half-life, and area under the concentration-versus-time curve from the last dose to infinity were 1,174 ± 186 ng/mL, 3.8 ± 1.8 hours, 23.2 ± 2.9 hours, and 38.6 ± 7.4 μg·h/mL, respectively, after a single dose and 1,185 ± 270 ng/mL, 3.0 ± 2.4 hours, 21.5 ± 5.3 hours, and 26.3 ± 5.7 μg·h/mL, respectively, at steady state after multiple doses. No adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Once-daily oral administration of amantadine at 5 mg/kg to orange-winged Amazon parrots maintained plasma concentrations above those considered to be therapeutic in dogs. Further studies evaluating safety and efficacy of amantadine in orange-winged Amazon parrots are warranted.

OBJECTIVE To compare the torsional mechanical properties of 2 external skeletal fixators (ESFs) placed with 2 intramedullary pin (IP) and transfixation pin (TP) size combinations in a model of raptor tibiotarsal bone fracture. SAMPLE 24 ESF-synthetic tibiotarsal bone model (polyoxymethylene) constructs. PROCEDURES Synthetic bone models were fabricated with an 8-mm (simulated fracture) gap. Four types of ESF-synthetic bone model constructs (6/group) were tested: a FESSA with a 1.6-mm IP and 1.6-mm TPs, a FESSA with a 2.0-mm IP and 1.1-mm TPs, an acrylic connecting bar with a 1.6-mm IP and 1.6-mm TPs, and an acrylic connecting bar with a 2.0-mm IP and 1.1-mm TPs. Models were rotated in torsion (5°/s) to failure or the machine angle limit (80°). Mechanical variables at yield and at failure were determined from load deformation curves. Effects of overall construct type, connecting bar type, and IP and TP size combination on mechanical properties were assessed with mixed-model ANOVAs. RESULTS Both FESSA constructs had significantly greater median stiffness and median torque at yield than both acrylic bar constructs; FESSA constructs with a 1.6-mm IP and 1.6-mm TPs had greatest stiffness of all tested constructs and lowest gap strain at yield. No FESSA constructs failed during testing; 7 of 12 acrylic bar constructs failed by fracture of the connecting bar at the interface with a TP. CONCLUSIONS AND CLINICAL RELEVANCE Although acrylic bar ESFs have been successfully used in avian patients, the FESSA constructs in this study were mechanically superior to acrylic bar constructs, with greatest benefit resulting from use with the larger TP configuration.

OBJECTIVE To compare a ventral and a left lateral endoscopic approach to coelioscopy in bearded dragons (Pogona vitticeps). ANIMALS 18 adult bearded dragons. PROCEDURES In a randomized crossover design involving 2 surgical approaches, anesthetized bearded dragons first underwent coelioscopy with a ventral approach (left lateral of midline next to the umbilicus; animal positioned in dorsal recumbency) or left lateral approach (intercostal; animal positioned in right lateral recumbency) and then with the alternate approach. A 2.7-mm × 18-cm, 30° oblique telescope with a 4.8-mm operating sheath and CO2 insufflation at 2 to 5 mm Hg were used. Ease of entry into the coelom and ease of visual examination of visceral structures were scored. RESULTS Both approaches were straightforward, with the left lateral approach requiring significantly more time than the ventral approach. Scores for ease of visual examination for the heart, lungs, liver, stomach, intestines, pancreas, gallbladder, left kidney, gonads, and fat body were good to excellent. Visual examination of the spleen and adrenal glands was difficult in most animals via either approach. The left kidney, testis, and vas deferens were easier to see with the left lateral approach, whereas the pancreas in females and gallbladder in both sexes were easier to see with the ventral approach. All bearded dragons recovered without complications from the procedures, except for one with nephritis, renal gout, and hepatic necrosis. CONCLUSIONS AND CLINICAL RELEVANCE Both coelioscopy approaches could be safely and effectively used in bearded dragons. Choice of approach should be based on the coelomic structures requiring evaluation.

BACKGROUND: More than half of homeless adults are of age ≥ 50 years. Falls are a common cause of morbidity in older adults in the general population. Risk factors for falls in the general population include poor health, alcohol use, and exposure to unsafe environments. Homeless adults aged ≥ 50 have a high prevalence of known risk factors and face additional potential risks. OBJECTIVES: To examine the prevalence of and risk of falling in a cohort of older homeless adults. DESIGN: Longitudinal cohort study with participant interviews every 6 months for 3 years; data were analyzed using generalized estimating equations (GEEs). PARTICIPANTS: Three hundred fifty adults aged ≥ 50, homeless at study entry, recruited via population-based sampling. MEASURES: The dependent variable is any falls in prior 6 months; independent variables include individual (i.e., illness, behaviors) and social/environmental (i.e., social support, experiencing violence, living unsheltered) factors. RESULTS: Over three quarters of participants were men (77.1%) and Black (79.7%). The median age was 58 (IQR 54, 61). At baseline, one third (33.7%) reported a fall in the prior 6 months. At follow-up visits, 23.1% to 31.2% of participants reported having fallen. In GEE models, individual risk factors (non-Black race, being a women, older age, functional impairment, urinary incontinence, history of stroke, and use of assistive devices, opioid, and marijuana) were associated with increased odds of falls. Environmental and social factors (spending any nights unsheltered (adjusted odds ratio (AOR) = 1.42, CI = 1.10–1.83) and experiencing physical assault (AOR = 1.67, CI = 1.18–2.37) were also associated. CONCLUSIONS: Older homeless adults fall frequently. Likely contributors include having a high prevalence of conditions that increase the risk of falls, compounded by heightened exposure to unsafe environments. Fall prevention in this population should target those at highest risk and address modifiable environmental conditions. Providing shelter or housing and addressing substance use could reduce morbidity from falls in homeless older adults.

CASE DESCRIPTION An 8-year-old sexually intact female eclectus parrot (Eclectus roratus) with a 4-day history of hyporexia and lethargy and a 1-day history of tenesmus was examined. CLINICAL FINDINGS Severe leukocytosis characterized by severe heterophilia and moderate monocytosis was present. Marked dilation of the proventriculus and ventriculus and ascites were identified by means of radiography, coelomic ultrasonography, and contrast-enhanced CT, with no clinically relevant motility noted on ultrasonography. Results of coelomic fluid analysis were consistent with pyogranulomatous effusion. Endoscopy of the upper gastrointestinal tract following proventricular and ventricular lavage showed a thick caseous plaque occupying 30% of the caudal proventricular mucosa. Abundant yeast organisms were evident during cytologic examination of a proventricular and ventricular wash sample, and fecal culture yielded Candida glabrata. TREATMENT AND OUTCOME The bird was treated with SC fluids, assisted feedings, nystatin, fluconazole, amoxicillin–clavulanic acid, enrofloxacin, gastroprotectants, maropitant, and analgesics and slowly improved during hospitalization. A marked decrease in proventricular dilation was evident on serial radiographs obtained over a 12-month period. One year after diagnosis, the bird was presented with a 1-week history of hyporexia and lethargy, and fecal culture grew C glabrata. Antifungal treatment was resumed for 3 months. The bird had no clinical signs of infection 16 months after this recurrence, and subsequent fecal cultures were negative for fungal growth. CLINICAL RELEVANCE Findings illustrate the importance of upper gastrointestinal endoscopy in diagnosing proventricular and ventricular dilation in birds and emphasize the need for long-term antifungal treatment and monitoring in birds with fungal infections.

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.

A 4-year-old castrated male lop-eared rabbit (Oryctolagus cuniculus) presented for right thoracic limb weakness of 1 week duration. Radiographs of the limb and adjacent spine were unremarkable. Despite treatment with meloxicam, limb weakness slowly progressed. Four months after initial presentation, neurologic examination revealed monoplegia without loss of pain perception in the right thoracic limb. Computed tomography scans showed multifocal regions of lobular, homogeneously contrast-enhancing tissue within the right ventral vertebral canal. This tissue extended into the right intervertebral foramina at C3-4 and C4-5 and at C5-6 and C6-7. A guarded-to-poor prognosis was given to the owners, who elected palliative care. Treatment with prednisolone and antibiotics resulted in short-term improvement. The rabbit became increasingly weak and passed away 4 weeks following the CT scan. Necropsy identified spinal cord compression due to a mass within the right vertebral canal that exited at C4-5 and continued into the right brachial plexus. The identified mass was morphologically and immunohistochemically consistent with a schwannoma. This case report documents the first clinical description of schwannoma of the spinal roots and brachial plexus in a rabbit.

A 4-year-old intact female Holland lop rabbit (Oryctolagus cuniculus) was referred for evaluation of a luxated right coxofemoral joint. Cranioventral luxation of the right femoral head was confirmed with pelvic radiographs at the referring veterinarian 3 days prior. On presentation, a nonweight bearing right pelvic limb lameness was appreciated. A closed hip reduction under anesthesia was attempted but not successful. The rabbit underwent an open coxofemoral reduction and the reduction was protected using a toggle rod stabilization method. A toggle pin was placed on the medial aspect of the acetabulum and fastened with suture to a second toggle pin on the lateral aspect of the femur, via a bone tunnel through the fovea capitus. Postoperative radiographs confirmed reduction of the coxofemoral joint and appropriate implant placement. Immediately following surgery, the rabbit began weight bearing on the right pelvic limb. Repeat evaluations showed a complete resolution to the rabbit's lameness, with no recurrence of the coxofemoral luxation. At rest, the right pelvic limb was intermittently mildly abducted; however, gait was not affected. This is the first case report to document a toggle pin fixation for successful repair of a coxofemoral luxation in a rabbit.

CASE DESCRIPTION A 4-year-old spayed female mixed-breed rabbit was evaluated because of a 3-year history of sneezing and nasal discharge that were refractory to medical management. CLINICAL FINDINGS Signs of chronic left-sided rhinitis and sinusitis were observed on physical examination and confirmed by CT evaluation. Lysis of the rostral aspect of the left maxillary bone and destruction of nasal turbinates were evident on CT images. TREATMENT AND OUTCOME Pararhinotomy of the left maxillary sinus through the facies cribrosa was performed. Purulent material was removed from the maxillary sinus recesses, a middle meatal antrostomy was completed to allow permanent drainage into the left middle nasal meatus, and the tissues were closed routinely. Microbial culture of a sample from the maxillary sinus recesses revealed Bordetella bronchiseptica, undetermined fastidious nonenteric bacteria, and Streptococcus viridans. Medical management was continued, and nasal discharge resolved but sneezing persisted. Increased sneezing and bilateral nasal discharge developed 1.5 years later; CT examination revealed right-sided rhinitis, and culture of a nasal swab sample revealed Bordetella spp, Staphylococcus spp, and Micrococcus spp. Right-sided pararhinotomy and middle meatal antrostomy were performed, and medical management continued. A subsequent recurrence was managed without additional surgery; 4 years after the initial surgery, the rabbit was still receiving medical treatment, with mild intermittent nasal discharge and sneezing reported. CLINICAL RELEVANCE This report describes a surgical approach for treatment of chronic rhinitis in companion rabbits with maxillary sinus involvement that included creation of a permanent drainage pathway from the maxillary sinus to the middle nasal meatus.

The homeless population is aging; older homeless adults may be at high risk of experiencing violent victimization. To examine whether homelessness is independently associated with experiencing physical and sexual abuse, we recruited 350 adults, aged 50 and older in Oakland, California, who met criteria for homelessness between July 2013 and June 2014. We interviewed participants at 6-month intervals for 3 years in Oakland about key variables, including housing status. Using generalized estimating equations, we examined whether persistent homelessness in each follow-up period was independently associated with having experienced physical or sexual victimization, after adjusting for known risk factors. The majority of the cohort was men (77.4%) and Black American (79.7%). At baseline, 10.6% had experienced either physical or sexual victimization in the prior 6 months. At 18-month follow-up, 42% of the cohort remained homeless. In adjusted models, persistent homelessness was associated with twice the odds of victimization (adjusted odds ratio [AOR] = 2.01; 95% confidence interval [CI]: [1.41, 2.87]). Older homeless adults experience high rates of victimization. Re-entering housing reduces this risk. Policymakers should recognize exposure to victimization as a negative consequence of homelessness that may be preventable by housing.

Background Early readmission amongst older safety-net hospitalized adults is costly. Interventions to prevent early readmission have had mixed success. The role of perceived social support is unclear. We examined the association of perceived social support in 30-day readmission or death in older adults admitted to a safety-net hospital. Methods This is an observational cohort study derived from the Support From Hospital to Home for Elders (SHHE) trial. Participants were community-dwelling English, Spanish and Chinese speaking older adults admitted to medicine wards at an urban safety-net hospital in San Francisco. We assessed perceived social support using the Multidimensional Scale of Perceived Social Support (MSPSS). We defined high social support as the highest quartile of MSPSS. We ascertained 30-day readmission and mortality based on a combination of participant self-report, hospital and death records. We used multiple/multivariable logistic regression to adjust for patient demographics, health status, and health behaviors. We tested for whether race/ethnicity modified the effect high social support had on 30-day readmission or death by including a race-social support interaction term. Results Participants (n = 674) had mean age of 66.2 (SD 9.0), with 18.8% White, 24.8% Black, 31.9% Asian, and 19.3% Latino. The 30-day readmission or death rate was 15.0%. Those with high social support had half the odds of readmission or death than those with low social support (OR = 0.47, 95% CI 0.26–0.88). Interaction analyses revealed race modified this association; higher social support was protective against readmission or death among minorities (AOR = 0.35, 95% CI 0.16–0.76) but increased likelihood of readmission or death among Whites (AOR = 3.7, 95% CI 1.07–12.9). Conclusion In older safety-net patients nearing discharge, high perceived social support may protect against 30-day readmission or death among minorities. Assessing patients’ social support may aid targeting of transitional care resources and intervention design. How perceived social support functions across racial/ethnic groups in health outcomes warrants further study. Trial registration NIH trials registry number ClinicalTrials.gov: NCT01221532.

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.

OBJECTIVE To describe a technique for endoscopic evaluation of the coelomic viscera of koi (Cyprinus carpio) and to evaluate the ability to visually examine coelomic structures by use of an approach cranial or caudal to the pelvic girdle. ANIMALS 16 subadult koi. PROCEDURES Koi were anesthetized with buffered tricaine methanesulfonate. Coelioscopic examination was performed via a ventral midline incisional approach cranial or caudal to the pelvic girdle. A 2.7-mm × 18-cm 30° oblique endoscope within a 4.8-mm operating sheath and infusion of saline (0.9% NaCl) solution was used. Ease of entry into the coelomic cavity and visual examination of structures were scored for each fish. Fish were euthanized 2 or 8 weeks after the procedure, and necropsy was performed. RESULTS The coelioscopic procedure was tolerated well, and all koi recovered uneventfully. For all fish, ease of entry and visual examination scores of the liver, intestines, gonads, heart, and anterior kidney were satisfactory to excellent. Visual examination of the posterior kidney and swim bladder was satisfactory to difficult, whereas the spleen and gallbladder were not visually identified. No significant differences were noted in entry or visual examination scores between the cranial and caudal approaches or between sexes. Minor complications included mild hemorrhage, rupture of the gonadal capsule, formation of adhesions between the viscera and incision site, and delayed healing of the incision. CONCLUSIONS AND CLINICAL RELEVANCE Diagnostic coelioscopy of koi appeared to be safe and effective. This procedure could have potential for use in examination of coelomic structures and disease diagnosis.

This report describes post-traumatic ocular lymphoma in 3 companion rabbits; 2 rabbits with unilateral disease and 1 with bilateral disease. Historical findings suggestive of a traumatic event included either external unilateral ocular trauma or bilateral phacoemulsification. Severe corneal changes, presence of an anterior chamber mass(es), low intraocular pressures, and ocular discomfort were noted on ophthalmic examinations. All eyes were treated for variable courses with standard ophthalmic topical medications (antibiotic, anti-inflammatories, and steroid) and systemic anti-inflammatories. Based upon progression of disease, all affected eyes were ultimately enucleated; lenticular capsular rupture and a round cell neoplasm effacing normal structures with variable mitotic indices were noted on histopathology. Neoplastic lymphocytes strongly expressed CD79a via immunohistochemistry and lacked expression for CD3, indicating B lymphocyte lineage and not of T cell lineage. A single animal had evidence of local metastasis to a regional lymph node. Post-traumatic sarcomas have been reported in this species previously, however, these cases are the first reports of this novel round cell variant, named post-traumatic ocular lymphoma due to the B cell lineage confirmed through immunohistochemistry. Clinicians should be aware of this clinical presentation and the possibility of metastasis when evaluating ocular pathology in this species.

We report a case of ventricular septal defect causing congestive heart failure in a two-year-old, male common degu (Octodon degus). The patient presented for anorexia and dental disease, and a grade 4/6 holosystolic cardiac murmur was detected on physical exam. Thoracic radiographs showed cardiomegaly and a diffuse interstitial pulmonary pattern, consistent with congestive heart failure. Echocardiography was supportive of a perimembranous ventricular septal defect exhibiting low-velocity left-to-right shunting, and biatrial enlargement. These diagnoses were confirmed on post-mortem exam, along with pulmonary edema and cardiomyocyte hypertrophy, degeneration, and regeneration. This is the first published account of a ventricular septal defect and congestive heart failure in a degu.