Emergency tracheotomy and subsequent tracheal resection and anastomosis in a blue crane (Anthropoides paradiseus).

CASE DESCRIPTION: A 7-year-old female blue crane (Anthropoides paradiseus) was initially evaluated after it had suddenly developed signs of respiratory distress following aspiration of a rock. Emergency tracheotomy had been performed, and the rock had been removed from the proximal cervical portion of the trachea. Fifty-one days later, the clinical signs had returned and the crane was reevaluated. CLINICAL FINDINGS: On reevaluation, no obvious external abnormalities were appreciated at the previous surgical site and no discharge was observed from the glottis. Computed tomography and tracheoscopy revealed marked tracheal stenosis and architectural collapse of the trachea at the previous surgery site. TREATMENT AND OUTCOME: Tracheal resection and anastomosis was performed to remove the stenotic tracheal segment. Histologic examination of the resected tracheal segment revealed pyogranulomas with intralesional coccobacilli, fungal hyphae consistent with Aspergillus spp, possible parasitic ova, and features suggestive of mild to moderate heterophilic and lymphoplasmacytic tracheitis. The crane was treated with piroxicam, ceftiofur crystalline free acid, terbinafine, and itraconazole. At a follow-up examination 12 weeks later, no abnormalities were appreciated, and the surgical site had completely healed. CLINICAL RELEVANCE: To the authors' knowledge, this is the first reported case of successful tracheal resection and anastomosis in a bird of the order Gruiformes. The surgical approach used for the blue crane may be useful for removal of tracheal foreign bodies in this and other long-necked avian species.

Evaluation of subcutaneous administration of alfaxalone-midazolam and dexmedetomidine-midazolam for sedation of ball pythons (Python regius).

OBJECTIVE: To evaluate SC administration of alfaxalone-midazolam and dexmedetomidine-midazolam for sedation of ball pythons (Python regius). ANIMALS: 12 healthy juvenile ball pythons. PROCEDURES: In a randomized crossover study, each snake was administered a combination of alfaxalone (5 mg/kg [2.3 mg/lb]) and midazolam (0.5 mg/kg [0.23 mg/lb]) and a combination of dexmedetomidine (0.05 mg/kg [0.023 mg/lb]) and midazolam (0.5 mg/kg), SC, with a washout period of at least 7 days between protocols. Respiratory and heart rates and various reflexes and behaviors were assessed and compared between protocols. Forty-five minutes after protocol administration, sedation was reversed by SC administration of flumazenil (0.05 mg/kg) alone or in combination with atipamezole (0.5 mg/kg; dexmedetomidine-midazolam protocol only). Because of difficulties with visual assessment of respiratory effort after sedative administration, the experiment was repeated for a subset of 3 ball pythons, with plethysmography used to assess respiration. RESULTS: Both protocols induced a similar level of moderate sedation with no adverse effects aside from transient apnea. Cardiopulmonary depression was more profound, but time to recovery after reversal was significantly shorter, for the dexmedetomidine-midazolam protocol than for the alfaxalone-midazolam protocol. Plethysmographic findings were consistent with visual observations and suggested that snakes compensated for a decrease in respiratory rate by increasing tidal volume amplitude. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that both protocols induced clinically relevant sedation in ball pythons and should be useful for minor procedures such as venipuncture and diagnostic imaging. However, caution should be used when sedating snakes with compromised cardiopulmonary function. (J Am Vet Med Assoc 2020;256:573-579.

Postmortem Evaluation of Reintroduced Migratory Whooping Cranes (Grus americana) in Eastern North America.

We reviewed necropsy records of 124 Whooping Cranes (Grus americana) recovered following reintroduction of 268 individuals from 2001 to 2016 in the eastern US. Causes of death were determined in 62% (77/124) of cases facilitated by active monitoring that limited decomposition and scavenging artifact. The greatest proportions of mortality were caused by predation (0.468; 95% confidence interval 0.356-0.580; 36/77), collision with power lines or vehicles (0.260; 0.162-0.358; 20/77), and gunshot (0.169; 0.085-0.253; 13/77). Six deaths were attributed to infection (0.078; 0.018-0.138; 6/77), including bacterial and fungal etiologies. Lead analysis of 50 liver samples yielded two results with elevated concentrations (3.65 and 10.97 ppm wet weight), and 10 bone samples from partial carcasses lacking suitable liver tissue resulted in one elevated result (48.82 ppm dry weight). These data indicate that underlying subclinical or clinical lead toxicosis may be a factor in up to 5% of deaths attributed to predation or impact trauma. Brain cholinesterase activity testing indicated no exposure to organophosphate or carbamate pesticides (mean±SD=17.32±2.90 µmol/min/g, 31/71). The causes of death and potential underlying factors summarized in this study constitute the first definitive mortality survey of migratory Whooping Cranes based on a high carcass recovery rate. Causes of death by infectious etiologies remained comparatively rare in this study, and occurred as single cases with no evidence of sustained transmission among reintroduced Whooping Cranes.

COMPARISON OF SUBCUTANEOUS ADMINISTRATION OF ALFAXALONE-MIDAZOLAM-DEXMEDETOMIDINE WITH KETAMINE-MIDAZOLAM-DEXMEDETOMIDINE FOR CHEMICAL RESTRAINT IN JUVENILE BLUE POISON DART FROGS (DENDROBATES TINCTORIUS AZUREUS).

Blue poison dart frogs (Dendrobates tinctorius azureus) are commonly maintained in zoological institutions and are becoming popular in the pet trade industry. Sedation or light anesthesia is required for safe and effective handling of this species. In this study, the sedative effects of subcutaneously administered alfaxalone-midazolam-dexmedetomidine (AMD) (20, 40, 5 mg/kg, respectively) and ketamine-midazolam-dexmedetomidine (KMD) (100, 40, 5 mg/kg, respectively) were compared in a prospective, randomized, blinded, crossover study in juvenile blue poison dart frogs (n = 10). Both protocols were partially reversed 45 min after administration of either protocol with subcutaneously administered flumazenil (0.05 mg/kg) and atipamezole (50 mg/kg). Heart rate, pulmonic respiratory rate, various reflexes, and behavioral parameters were monitored after drug administration. Both protocols resulted in rapid loss of righting reflex [median (range): AMD, 5 min (5-5 min); KMD, 5 min (5-10 min)]. Time to complete recovery was similar with both protocols (mean ± SD: AMD, 97.5 ± 11.4 min; KMD, 96.5 ± 25.4 min). The AMD protocol resulted in pulmonic respiratory depression, whereas no significant difference in heart rate was found between the two protocols. All frogs were observed eating within 24 hr of chemical restraint. Gastric prolapses occurred in four frogs (AMD 3, KMD 1) that were easily reduced with a cotton-tip application. No other adverse reactions were observed. The results of this study provide two different subcutaneous chemical restraint protocols in juvenile blue poison dart frogs.

Primary amebic meningoencephalomyelitis caused by Naegleria fowleri in a south-central black rhinoceros (Diceros bicornis minor).

CASE DESCRIPTION A 20-year-old female south-central black rhinoceros (Diceros bicornis minor) was evaluated because of an acute onset of CNS deficits. CLINICAL FINDINGS The rhinoceros had no history of illness. Clinical signs included acute lethargy, ataxia, and decreased appetite. Hematologic abnormalities included leukocytosis with neutrophilia and a profound left shift. Results of serum biochemical analysis revealed hypophosphatemia but no other abnormalities. Results of a quantitative PCR assay for West Nile virus and an assay for anti-Neosporum caninum antibodies in serum were negative; the patient was seropositive for multiple Leptospira serovars. TREATMENT AND OUTCOME Antimicrobials and anti-inflammatory agents were administered, but the condition of the rhinoceros worsened overnight; despite treatment with additional anti-inflammatory and antimicrobial agents, IV fluids, and thiamine, it became obtunded and died of respiratory arrest ≤ 24 hours later. Necropsy revealed severe, diffuse, suppurative, and histiocytic meningo-encephalomyelitis involving the cerebrum, cerebellum, and spinal cord. Amebic trophozoites were observed on histologic examination of affected tissue. Infection with Naegleria fowleri was confirmed by results of immuno-histochemical analysis and a multiplex real-time PCR assay. CLINICAL RELEVANCE Findings suggested that south-central black rhinoceros are susceptible to the free-living ameba N fowleri. Ameba-induced meningoencephalomyelitis should be considered as a differential diagnosis for rhinoceros that have an acute onset of neurologic signs. Diagnosis of N fowleri infection in an animal has a profound public health impact because of potential human exposure from the environment and the high fatality rate in people with N fowleri infection.

Venous Blood Analytes and Osmolality of Rehabilitated Juvenile Black-bellied Whistling Ducks (Dendrocygna autumnalis).

Venous blood samples were collected from 129 apparently healthy, rehabilitated juvenile black-bellied whistling ducks (Dendrocygna autumnalis) immediately before release from rehabilitation. Blood gas, electrolyte, and select biochemical and hematologic values were analyzed by using a point-of-care analyzer, and complete blood cell counts and osmolality were determined. Most biochemical analyte values were distributed parametrically, while most hematologic values were nonparametrically distributed. Calculated osmolality values were in poor agreement with measured osmolality values, and values of packed cell volume had poor agreement with hematocrit values determined with the i-STAT 1. The physiologic values reported provide vital information to assess individual duck health and guide fluid therapy in captivity and may prove useful to assess free-living population health of this duck species.

Pharmacokinetics of subcutaneously administered hydromorphone in bearded dragons (Pogona vitticeps) and red-eared slider turtles (Trachemys scripta elegans).

OBJECTIVE: To determine pharmacokinetic dosing strategy in bearded dragons (Pogona vitticeps) and red-eared sliders (Trachemys scripta elegans) based on two subcutaneously (SC) administered doses of hydromorphone (0.5 and 1.0 mg kg-1). STUDY DESIGN: Randomized crossover study. ANIMALS: Six healthy adult bearded dragons, seven healthy adult red-eared slider turtles. METHODS: Hydromorphone (0.5 and 1.0 mg kg-1; 2 mg mL-1) was administered SC dorsolateral to the scapulae in the bearded dragons and between the head and thoracic limb of the red-eared slider turtles. Blood was collected for hydromorphone plasma concentration analysis from the ventral tail vein in bearded dragons and subcarapacial sinus in turtles before (time 0) hydromorphone administration and at 0.5, 1, 6, 12 and 24 hours. RESULTS: The half-life of hydromorphone administered at 0.5 and 1.0 mg kg-1 was 2.54 and 3.05 hours in bearded dragons and 2.67 and 2.01 hours in red-eared sliders, respectively. The maximum plasma concentrations for 0.5 and 1.0 mg kg-1 were 142 and 369 ng mL-1 in bearded dragons and 1610 and 5142 ng mL-1 in red-eared sliders, respectively. Peak plasma concentrations were detected at 30 minutes for both species. Hydromorphone administered at both dosages provided plasma concentrations of 13-14 ng mL-1 for at least 24 hours in bearded dragons and of 5-6 ng mL-1 for at least 12 hours in red-eared sliders. Clinical sedation was observed for up to 1 hour posthydromorphone (1.0 mg kg-1) administration for five of six bearded dragons characterized by low body carriage and decreased response to stimuli. No evidence of clinical sedation was observed in red-eared sliders at either dose. CONCLUSIONS AND CLINICAL RELEVANCE: Recommended dosing strategy for hydromorphone is 0.5 mg kg-1 administered SC every 24 hours in bearded dragons and every 12-24 hours in red-eared sliders.

COMPARISON OF A SMARTPHONE-BASED ELECTROCARDIOGRAM DEVICE WITH A STANDARD SIX-LEAD ELECTROCARDIOGRAM IN THE ATLANTIC BOTTLENOSE DOLPHIN ( TURSIOPS TRUNCATUS).

A bipolar, single-lead electrocardiogram (ECG) device is capable of recording ECGs with an integrated smartphone application. To determine the utility of this device, phone-based ECGs (pECG) were compared with standard six-lead ECGs (sECG) in four female Atlantic bottlenose dolphins ( Tursiops truncatus) at the National Aquarium. Study animals were trained to haul out onto a dry deck in ventral recumbency and allow simultaneous 30-sec ECG acquisition using the two devices. The pECG device was held against the thoracic wall caudal to the left axilla. The sECGs were recorded in the frontal plane. Instantaneous heart rates were obtained from identical QRS complexes on both ECGs. Three boarded cardiologists independently evaluated the rhythm and the polarity of the QRS depolarization for each recording and the results were compared. The mean heart rate was 80 beats/min (range 62-92 beats/min) and 80 beats/min (range 60-92 beats/min) for the pECG and sECGs, respectively. All four dolphins displayed sinus respiratory arrhythmia, and one animal had occasional atrial premature contractions. Rhythm diagnosis and QRS polarity were identical for the pECG and sECG. Dolphin vocalizations created artifacts on the pECG that were not present on the sECG, so pECGs had to be acquired without vocalization. The pECG appears to be an accurate and useful method to monitor the heart rate in Atlantic bottlenose dolphins. This system is inexpensive and portable, making it valuable for health examinations, transport monitoring, and stranding responses.

Bioavailability and biochemical effects of diclofenac sodium 0.1% ophthalmic solution in the domestic chicken (Gallus gallus domesticus).

OBJECTIVE: To determine if topical ophthalmic diclofenac sodium 0.1% solution alters renal parameters in the domestic chicken, and to determine if the drug is detectable in plasma after topical ophthalmic administration. ANIMALS: Thirty healthy domestic chickens. PROCEDURES: Over 7 days, six birds were treated unilaterally with one drop of artificial tear solution (group 1), 12 birds were treated unilaterally (group 2) and 12 bilaterally (group 3) with diclofenac sodium 0.1% ophthalmic solution. Treatments were provided every 12 h in all groups. Pre- and post-treatment plasma samples from all birds were evaluated for changes in albumin, total protein, and uric acid. Post-treatment samples of all birds, collected 15 min post-administration, were analyzed by high-performance liquid chromatography with mass spectrometry for diclofenac sodium detection. A randomly selected renal sample from each group was submitted for histopathologic review. RESULTS: Changes in pre- and post-treatment plasma albumin were significant (P < 0.05) in groups 2 and 3, but not for group 1. Pre- and post-treatment changes in total protein and uric acid were not significant for any group. Diclofenac sodium was not detectable (limit of detection = 0.10 ng/mL) in plasma samples from birds in group 1. Post-treatment concentration of diclofenac in group 3 was statistically greater than group 2 (P = 0.0008). Histopathologic changes did not identify diclofenac-induced acute renal tubular necrosis. CONCLUSIONS: Ophthalmic diclofenac sodium 0.1% administered topically every 12 h in one or both eyes for 7 days is detectable in systemic circulation in the domestic chicken, but does not cause overt significant changes in plasma uric acid or total protein.

Removal of a Presumed Peripheral Cerebral Cyst via Craniectomy in a Crested Pekin Duck ( Anas platyrhynchos f dom).

A juvenile, male crested pekin duck ( Anas platyrhynchos f dom) was presented for neurologic signs suggestive of cerebellar disease. Physical examination revealed microphthalmia, erratic head movements, and ataxia. Computed tomography scan of the head and neck regions revealed 2 full-thickness skull-bone defects within the caudal portion of the cranium. The cerebellum appeared to be ventrally compressed by a homogeneous, triangular, fluid-attenuating region (0-10 Hounsfield units). A craniectomy was performed, and a presumed peripheral cerebral cyst was removed with suction and gentle dissection. No postoperative complications occurred, and the patient showed clinical improvement for 5 months after surgery. However, after 5 months, the owners elected euthanasia because of poor prognosis after finding the duck minimally responsive in a water enclosure. At necropsy, a thin-walled, epithelial structure was present in meninges and was adhered to the skull at the presumed surgical site.

PHARMACOKINETIC PROPERTIES OF A SINGLE ADMINISTRATION OF ORAL GABAPENTIN IN THE GREAT HORNED OWL (BUBO VIRGINIANUS).

Gabapentin (1-[aminomethyl] cyclohexane acetic acid) is a γ-aminobutyric acid analogue that has been shown to be efficacious for neuropathic pain control in humans. Plasma gabapentin concentrations >2 µg/ml are considered effective in treating epilepsy in humans and are suggested to provide analgesia for neuropathic pain. This study investigated the pharmacokinetics of a single oral dose of gabapentin suspension (11 mg/kg) in great horned owls ( Bubo virginianus ). Plasma gabapentin concentrations were determined in six healthy birds for 48 hr using high-performance liquid chromatography with mass spectrometric detection. Plasma gabapentin concentrations were estimated by noncompartmental pharmacokinetic analysis. The harmonic mean (±SD) maximum concentration (Cmax), time to maximum concentration (Tmax), and elimination half-life (tv2λZ) for gabapentin (11 mg/kg) were 6.17±0.83 µg/ml, 51.43±5.66 min, and 264.60±69.35 min, respectively. In this study, plasma gabapentin concentrations were maintained above 2 µg/ml for 528 min (8.8 hr), suggesting that gabapentin administered orally every 8 hr may be appropriate in great horned owls.