Use of alfaxalone in bearded dragons (Pogona vitticeps): optimizing pharmacodynamics and evaluating cardiogenic effects via echocardiography.

OBJECTIVE: Bearded dragons (Pogona vitticeps), a popular zoological companion species, frequently require sedation for procedures. A novel formulation of alfaxalone with preservatives was FDA approved for 28-day use after the vial is breached. Research has been performed in squamate species using alfaxalone without preservatives at various doses and routes of administration, but it is unknown whether preservatives affect quality of sedation or cardiac function. ANIMALS: 10 bearded dragons. PROCEDURES: This complete crossover study evaluated the pharmacodynamic effects of alfaxalone with preservatives administered to bearded dragons via intracoelomic (ICo; n = 10), SC (10), IM (9), and IV (9) injection at 15 mg/kg. RESULTS: Deep sedation was achieved in 9 of 10 ICo, 8 of 10 SC, 8 of 9 IM, and 9 of 9 IV administrations. Heart rate significantly decreased from baseline for ICo (P = .008; median heart rate, 46), IM (P = .018; 54), and IV (P = .033; 54) routes, but maintained within clinically acceptable limits. Respiratory rate significantly decreased from baseline for ICo (P = .011; median respiratory rate, 30), SC (P = .024; 12), IM (P = .028; 12), and IV (P = .043; 12) routes. Spontaneous ventilation was retained during all events. Time to first effects was significantly sooner with IV (0 min) administration compared with ICo (P = .02; 5 min) and IM (P = .008; 5 min). Time to loss and recovery of withdrawal, righting reflex, deep pain, and purposeful movement were not significantly different between routes of administration. End-systolic volume was the only echocardiographic parameter significantly affected by IV sedation. CLINICAL RELEVANCE: Sedation quality was most consistent via IV administration at 15 mg/kg, and minimal changes in cardiac function were observed.

Clinical disease and treatment of Leptospira kirschneri sv Grippotyphosa in a Sumatran tiger (Panthera tigris sumatrae).

CASE DESCRIPTION: A 12-year-old sexually intact male zoo-managed Sumatran tiger (Panthera tigris sumatrae) was evaluated for a 3-day history of vomiting, hyporexia, and lethargy. Radiographs were supportive of gastrointestinal obstruction, and an exploratory laparotomy was performed. CLINICAL FINDINGS: Diffuse tan foci were present on the liver parenchyma, and the tiger became icteric throughout the procedure. Hepatic histopathology and immunohistochemistry resulted in a diagnosis of leptospirosis. Serum microagglutination testing for Leptospira spp antibody titers were positive for L kirschneri serovar Grippotyphosa, rising from 1:400 to 1:3,200 in 2 days. TREATMENT AND OUTCOME: The tiger was treated with antimicrobials, ursodiol, and mirtazapine, and increased biosecurity measures were instituted. Free-ranging wildlife on grounds were trapped, euthanized, and submitted for necropsy to screen for disease vectors. The tiger's urine was intermittently opportunistically collected from the enclosure and remained PCR assay negative for Leptospira spp until being positive once again on day 595. Although the tiger was without clinical signs at that time, antimicrobial therapy and increased biosecurity protocols were instituted a second time until urinary Leptospira shedding was confirmed to have stopped. By 1,071 days after initial presentation, the tiger remained nonclinical, with no additional urinary shedding episodes. CLINICAL RELEVANCE: While domestic and nondomestic free-ranging felids have been reported as subclinical Leptospira spp carriers, this report indicates the clinical importance of leptospirosis when a tiger presents with generalized gastrointestinal signs and icterus. Due to the zoonotic potential, biosecurity measures are necessary. This patient had a clinically successful outcome with antimicrobial therapy and supportive care.

OPTIMIZING THE PHARMACODYNAMICS AND EVALUATING CARDIOGENIC EFFECTS OF THE INJECTABLE ANESTHETIC ALFAXALONE IN PRAIRIE RATTLESNAKES (CROTALUS VIRIDIS).

North American vipers are commonly housed in zoological institutions or studied as free-ranging populations. Because of their venomous predatory and defensive mechanism, sedation or anesthesia is frequently employed to facilitate safe handling and medical procedures, especially of the head. A new formulation of alfaxalone with proprietary preservatives was recently approved and indexed for 28-d use post-vial puncture. Pharmacodynamic effects of alfaxalone in its prior formulation have been researched in nonvenomous species, but the optimal dose and route of administration in vipers have not been reported. In part one, 10 prairie rattlesnakes (Crotalus viridis) participated in a complete four-route crossover study evaluating 20 mg/kg alfaxalone administered intracoelomically (ICo), SC cranial to the heart, IM cranial to the heart, and IV in the ventral coccygeal vein. HR significantly decreased from baseline during IV (P= 0.024), IM (P= 0.024), and SC (P= 0.028) administration. Respiratory rate significantly decreased following alfaxalone delivered IV (P = 0.027). Time to first effects was significantly faster in IV compared with IM (P= 0.01), SC (P= 0.001), and ICo (P= 0.036). All IV and IM administrations resulted in deep sedation, but 70% of the IV and 10% of the IM sedation events resulted in apnea and required intermittent positive ventilation via endotracheal tube. Fifty percent of the ICo sedation events and 10% of the SC sedation events did not result in sedation. One successful SC sedation event resulted in apnea. In part two, echocardiograms were performed in the same rattlesnakes at baseline and at maximum effect of sedation with 20 mg/kg alfaxalone administered IM. Cardiac contractility and output were unaffected. Administration of alfaxalone at 20 mg/kg IM cranial to the heart should facilitate safe handling and minimally invasive procedures in prairie rattlesnakes and related species.

EVALUATION OF THE INTER- AND INTRAINDIVIDUAL AGREEMENT OF A PODODERMATITIS SCORING MODEL IN GREATER FLAMINGOS (PHOENICOPTERUS ROSEUS).

Pododermatitis is an important cause of morbidity and mortality in flamingos under human care; management and treatment options vary widely based on subjective assessment from veterinarians or animal care staff (ACS). The objective of this study was to evaluate the agreement of pododermatitis severity scores assigned by veterinarians, ACS, and veterinary students when given a standardized rubric. Twenty-four greater flamingos (Phoenicopterus roseus) from a single zoo-managed flock were evaluated over time for pododermatitis. The individual feet of each bird were imaged, blinded, randomized, and scored for hyperkeratosis, fissures, nodules, papillomatous growth, and overall subjective score by seven evaluators (three veterinary specialists, two ACS, and two veterinary students) using a previously established flamingo pododermatitis scoring rubric. Interindividual reliability between evaluators and intraindividual agreement among specialists was determined. Reliable interindividual agreement was seen for fissures (Krippendorff's α [KA] = 0.807) between all seven evaluators, whereas the other individual lesions had very low reliability. Between the specialists, fissures had low interindividual reliability (KA = 0.782). Two specialists had strong intraindividual agreement for fissure score and one specialist had strong intraindividual agreement for overall subjective score (Cohen's κ [CK] 0.8-0.9, P < 0.01). Hyperkeratosis, papillomatous growth, nodules, and overall subjective score had low to moderate inter- and intraindividual reliability or agreement (KA, 0.06-0.49; CK, 0.02-0.8). In conclusion, the current scoring method for flamingo pododermatitis does not supply a reliable method for tracking foot health based on images alone across timepoints, except for fissures. Further analysis of the scoring system being used during a physical examination is warranted.