Pyrethroid-associated nephrotoxicity in channel catfish, Ictalurus punctatus, and blue catfish, I. furcatus, at a public aquarium.

Over the course of an approximately 11-month period, an outdoor, freshwater, mixed species, recirculating, display system at a public aquarium experienced intermittent mortalities of channel catfish (Ictalurus punctatus) and blue catfish (I. furcatus). Catfish acutely presented for abnormal buoyancy, coelomic distention, and protein-rich coelomic effusion. Gross lesions typically involved massive coelomic distension with protein-rich effusion, generalized edema, and gastric hemorrhage and edema. Microscopically, primary lesions included renal tubular necrosis, gastric edema with mucosal hemorrhages, and generalized edema. Aerobic culture and virus isolation could not recover a consistent infectious agent. Intracoelomic injection of coelomic effusion and aspirated retrobulbar fluid from a catfish into naïve zebrafish (bioassay) produced peracute mortality in 3 of 4 fish and nervous signs in the fourth compared with 2 saline-injected control zebrafish that had - no mortality or clinical signs. Kidney tissue and coelomic effusion were submitted for gas chromatography tandem mass spectrometry by multiple reaction monitoring against laboratory standards, which detected the presence of multiple pyrethroid toxins, including bioallethrin, bifenthrin, trans-permethrin, phenothrin, and deltamethrin. Detection of multiple pyrethroids presumably reflects multiple exposures with several products. As such, the contributions of each pyrethroid toward clinical presentation, lesion development, and disease pathogenesis cannot be determined, but they are suspected to have collectively resulted in disrupted osmoregulation and fluid overload due to renal injury. Pesticide-induced toxicoses involving aquarium fish are rarely reported with this being the first description of pyrethroid-induced lesions and mortality in public aquarium-held fish.

Reptile assisted reproductive technologies: can ART help conserve 300 million years of evolution by preserving extant reptile biodiversity?

Biodiversity loss is the greatest environmental problem threatening ecosystem, animal, and human health. Anthropogenic induced changes to climate, habitat, disease, species distributions, poaching, and unsustainable trade have accelerated extinction rates in all vertebrates, including reptiles. Preventing reptile extinctions will require humans to acknowledge these losses and develop ex situ and in situ plans to preserve them. Assisted reproductive technologies (ART) are management tools used to protect numerous vertebrate taxa; however, progress in developing ART for reptiles has lagged. Creating functional and sustainable reptile ART will strengthen our conservation capacity by capturing genetic material from select individuals to overcome natural or manmade boundaries. Utilising short-term gamete storage and genome resource banking, in conjunction with timed artificial insemination (AI) or ex ovo incubation, could lead to profound advances in reptile conservation, mitigating the loss of reptile biodiversity. In this article, we review ART reptile research completed since the 1970s. Topics include AI, hormonal control of reproduction, gamete collection, gamete storage, and genome resource banking. Additionally, we review the potential application of advanced reproductive methodologies, including in vitro /ex ovo fertilisation, intracytoplasmic sperm injection, cloning (somatic cell nuclear transfer), and genetic editing.

Sex, drugs and rock iguanas: testicular dynamics and plasma testosterone concentrations could predict optimal semen collection times in Cyclura.

Iguanas are the most endangered family of reptiles, with 77% categorised as threatened or near threatened. Further, Cyclura is the most endangered reptile genus, with all 12 species considered threatened. Therefore, it is vital that we develop assisted reproductive technologies for Cyclura spp. to enhance their conservation efforts. The goals of this study were to collect semen, and to measure testicle size and testosterone concentrations in Grand Cayman rock iguana hybrids (Cyclura lewisi ×nubila (CLN)) and rhinoceros rock iguanas (Cyclura cornuta (CC)). A prospective longitudinal study was performed in 9.0 CLN and 9.0 CC during their reproductive season in southern Florida (February-July). Serial testicle ultrasound measurements and plasma testosterone concentrations were collected monthly. Testicle measurements (length (L), width (W), height (H)) were collected and testicle volume (V ) was estimated using the equation V =0.52(LW 2 ). There were significant differences in testicle L, W, H and V for both species. Testicle size peaked for CLN and CC in April and May respectively. Plasma testosterone concentrations increased from baseline during February, March and April in CLN and in March, April and May in CC. Ultrasound testicle measurements could be used to predict when to collect semen in these seasonally monocyclic iguanas.

COMPARISON OF SURFACE, ESOPHAGEAL, AND CLOACAL TEMPERATURES IN DIFFERENT REPTILE SPECIES.

The objective of this study was to compare surface, esophageal, and cloacal temperatures in awake iguanas, chameleons, and snakes at two different ambient temperatures and in alligators at one ambient temperature. Surface, esophageal, and cloacal temperatures were measured in all animals twice, with exception of the alligators, where temperatures were taken once. The first set of temperature readings was done at lower environmental temperature. An analysis of variance (ANOVA) with a mixed-effect model was used to analyze the temperature difference between esophageal and cloacal temperature against each other, and against surface temperature. Significance was set at P < 0.05. In all animals, surface, esophageal, and cloacal temperatures increased significantly (P < 0.0001) with increased ambient temperature. Esophageal and cloacal temperature were not significantly different from each other in iguanas and chameleons at lower environmental temperature or in snakes and chameleons at high ambient temperature. In snakes, esophageal temperature 26.1 ± 1.6°C was significantly higher than cloacal temperature 25.2 ± 0.9°C (P = 0.0016) at lower ambient temperature. In alligators no difference between esophageal and cloacal temperature was observed at the given ambient temperature. Surface temperature was significantly lower than esophageal and cloacal temperature in all species investigated, except iguanas at lower ambient temperature. The results of this study suggest that in healthy awake iguanas and chameleons at any ambient temperature and in snakes at high ambient temperature, cloacal temperatures are reflective of esophageal temperature in the species evaluated. In alligators, rectal temperature reflected esophageal temperature at the given ambient temperature. Surface temperature in contrast was underestimating esophageal temperature in all species investigated.

Dental onlay bridge-like prosthesis in three koalas (Phascolarctos cinereus): the use of Premise trimodal composite to prevent interproximal Eucalyptus spp. retention and infection.

Three koalas (Phascolarctos cinereus) presented with moderate to severe interproximal space accumulation with Eucalyptus spp. at the San Diego Zoo. Premise trimodal composite was used to create dental onlay bridge-like prostheses to eliminate open, enlarged interproximal spaces. The prostheses prevented further leaf material accumulation within the interproximal spaces and consequently reduced periodontal disease. Aesthetically, the prosthesis replicates normal tooth coloration and appearance and wears at a similar rate to surrounding teeth. Prosthetic repair or replacement may be required, so periodic examination every 3-6 mo is recommended.

Bayesian Decision Analysis: An Underutilized Tool in Veterinary Medicine.

Bayesian inference and decision analysis can be used to identify the most probable differential diagnosis and use those probabilities to identify the best choice of diagnostic or treatment among several alternatives. In this retrospective case analysis, we surveyed three experts on the prior probability of several differential diagnoses, given the signalment and history of a ferret presenting for lethargy and anorexia, and the conditional probability of different clinical findings (physical, bloodwork, imaging, etc.), given a diagnosis. Using these data and utility estimates provided by other clinicians, we constructed a decision tree to retrospectively identify the optimal treatment choice between exploratory laparotomy and medical management. We identified medical management as the optimal choice, in contrast to the original clinical team which performed an exploratory laparotomy. We discuss the potential cognitive biases of the original clinical team. We also discuss the strengths, e.g., shared decision making, and limitations of a Bayesian decision analysis in the veterinary clinic. Bayesian decision analysis can be a useful tool for retrospective case analysis and prospective decision making, especially for deciding on invasive interventions or end-of-life care. The dissimilarity of expert-derived probability estimates makes Bayesian decision analysis somewhat challenging to apply, particularly in wide-ranging specialties like zoological medicine.

Plasma and tissue enzyme activities of banded water snakes (Nerodia fasciata) and diamondback water snakes (Nerodia rhombifer).

OBJECTIVE: To measure plasma and tissue activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase (AST), creatine kinase, and γ-glutamyltransferase in 2 snake species. ANIMALS: 6 banded water snakes (Nerodia fasciata) and 6 diamondback water snakes (Nerodia rhombifer). PROCEDURES: Blood was collected via the ventral tail vein to measure plasma enzyme activities. Animals were then euthanized, and samples of 9 tissues were collected from each snake: skeletal muscle, cardiac muscle, liver, spleen, lung, kidney, testicle, pancreas, and gallbladder. Tissues were frozen for 30 days, then homogenized and processed. Supernatants were collected and analyzed within 24 hours of processing. A linear mixed model was used to determine differences in enzyme activity between tissues and species and assess interactions between tissues and species. RESULTS: Activities of all enzymes were found to differ significantly among tissues. There were also significant differences between species for all enzyme activities, except AST activity. The kidney had the highest alanine aminotransferase and γ-glutamyltransferase activities. Alkaline phosphatase activity was significantly highest in liver and kidney tissues than in other tissue. Creatine kinase activity was highest in skeletal muscle, followed by cardiac muscle and kidney. AST activity was present in all tissues evaluated, but was highest in liver, kidney, and cardiac muscle in both species. CLINICAL RELEVANCE: Results reinforced the importance of characterizing the origin of tissue enzymes in reptiles to improve our understanding of biochemistry results and highlighted the differences that can exist in tissue enzyme activities between closely related species.

Serum concentrations of canine pancreatic lipase immunoreactivity and C-reactive protein for monitoring disease progression in dogs with acute pancreatitis.

BACKGROUND: Reliable biomarkers for monitoring disease progression and management in dogs with acute pancreatitis have not been described. OBJECTIVE: To determine if serum concentrations of canine pancreatic lipase immunoreactivity (cPLI) and C-reactive protein (CRP) can be used as biomarkers for disease progression in hospitalized dogs with acute pancreatitis. ANIMALS: Thirteen hospitalized dogs with acute pancreatitis diagnosed based on clinical signs, serum cPLI concentrations, and imaging findings were enrolled. METHODS: Serum cPLI and CRP concentrations were determined before and then daily during hospital management and 1 week after hospital discharge. Modified canine activity index (MCAI) and canine acute pancreatitis clinical severity index (CAPCSI) scores were calculated daily for each patient while hospitalized. RESULTS: The MCAI scores (P = .03) but not CAPCSI scores (P = .31) were significantly different between dogs that survived to discharge (n = 11) and those that did not (n = 2). Serum cPLI concentration was positively correlated with MCAI (rho = 0.42; P = .01). Serum CRP concentration also was positively correlated with the MCAI (rho = 0.42, P = .01). CONCLUSIONS: Serum cPLI and possibly CRP could be used as objective biomarkers for clinical changes in hospitalized dogs with acute pancreatitis. Additional studies involving larger numbers of dogs would be warranted to evaluate the broader impact of these findings.

Determining the Effects of Serial Injections of Pregnant Mare Serum Gonadotropin on Plasma Testosterone Concentrations, Testicular Dynamics, and Semen Production in Leopard Geckos (Eublepharis macularius).

Reptiles are highly susceptible to anthropogenic activities as a result of their narrow geographical ranges and habitat specialization, making them a conservation concern. Geckos represent one of the mega-diverse reptile lineages under pressure; however, limited assisted reproductive technologies currently exist for these animals. Exogenous pregnant mare serum gonadotropin (PMSG) has been found to exhibit follicle stimulating hormone-like action and has been routinely used to alter reproductive hormones of vertebrates in assisted reproductive protocols. The purpose of this study was to determine the effects of serial injections of 20 IU and 50 IU PMSG on circulating testosterone concentrations, testicular dynamics, and semen production in a model species of gecko. Twenty-four captive-bred, adult, male leopard geckos (Eublepharis macularius) were divided into three treatment groups and administered a once-weekly injection of either PMSG or saline for a total of nine weeks. Ultrasonographic testicular measurements, electrostimulation for semen collection, and venipuncture were performed on days 0, 21, 42, and 63. Right unilateral orchidectomies and epididymectomies were performed in all animals on day 63; tissues were submitted for histopathology. PMSG treated geckos had significantly higher testicular volumes and weights, spermatozoa motility, and spermatozoa concentrations compared with controls. However, there were no significant differences in testosterone concentrations by treatment or time. Under the conditions outlined, PMSG is effective at stimulating spermatogenesis and increasing testicular size, but not effective at increasing testosterone concentrations in the leopard gecko between October-December in the Northern hemisphere.

Longitudinal and Cross-Sectional Sampling of Serpentovirus (Nidovirus) Infection in Captive Snakes Reveals High Prevalence, Persistent Infection, and Increased Mortality in Pythons and Divergent Serpentovirus Infection in Boas and Colubrids.

The aim of this study of serpentovirus infection in captive snakes was to assess the susceptibility of different types of snakes to infection and disease, to survey viral genetic diversity, and to evaluate management practices that may limit infection and disease. Antemortem oral swabs were collected from 639 snakes from 12 US collections, including 62 species, 28 genera, and 6 families: Pythonidae (N = 414 snakes; pythons were overrepresented in the sample population), Boidae (79), Colubridae (116), Lamprophiidae (4), Elapidae (12), and Viperidae (14). Infection was more common in pythons (38%; 95% CI: 33.1-42.4%), and in boas (10%; 95% CI: 5.2-18.7%) than in colubrids (0.9%, 95% CI: <0.01-4.7%); infection was not detected in other snake families (lamprophiids 0/4, 95% CI: 0-49%; elapids 0/12, 95% CI: 0-24.2%; and vipers 0/14, 95% CI: 0-21.5%), but more of these snakes need to be tested to confirm these findings. Clinical signs of respiratory disease were common in infected pythons (85 of 144). Respiratory signs were only observed in 1 of 8 infected boas and were absent in the single infected colubrid. Divergent serpentoviruses were detected in pythons, boas, and colubrids, suggesting that different serpentoviruses might vary in their ability to infect snakes of different families. Older snakes were more likely to be infected than younger snakes (p-value < 0.001) but males and females were equally likely to be infected (female prevalence: 23.4%, 95% CI 18.7-28.9%; male prevalence: 23.5%, 95% CI 18-30.1%; p-value = 0.144). Neither age (p-value = 0.32) nor sex (p-value = 0.06) was statistically associated with disease severity. Longitudinal sampling of pythons in a single collection over 28 months revealed serpentovirus infection is persistent, and viral clearance was not observed. In this collection, infection was associated with significantly increased rates of mortality (p-value = 0.001) with death of 75% of infected pythons and no uninfected pythons over this period. Offspring of infected parents were followed: vertical transmission either does not occur or occurs with a much lower efficiency than horizontal transmission. Overall, these findings confirm that serpentoviruses pose a significant threat to the health of captive python populations and can cause infection in boa and colubrid species.

Pain and Its Control in Reptiles.

Reptiles have the anatomic and physiologic structures needed to detect and perceive pain. Reptiles are capable of demonstrating painful behaviors. Most of the available literature indicates pure µ-opioid receptor agonists are best to provide analgesia in reptiles. Multimodal analgesia should be practiced with every reptile patient when pain is anticipated. Further research is needed using different pain models to evaluate analgesic efficacy across reptile orders.

Evidence-Based Advances in Reptile Medicine.

Evidence-based medicine allows veterinarians to practice high-quality medicine, because the basis for all decision making is quantitative, objective, and reproducible. Case reports and case series are limited in their scope and application. Cross-sectional studies, likewise, cannot provide answers to specific variable testing with a temporal application. It is essential for the reptile specialty to expand into case-control studies, cohort studies, and experimental/intervention studies. Unfortunately, much of the reptile literature remains limited to descriptive studies. This article reviews current evidence-based topics in reptile medicine and shares how everyone practicing in the field can contribute to improving this specialty.

Reproductive Medicine in Freshwater Turtles and Land Tortoises.

Chelonian reproductive medicine is an extremely important facet to ensuring captive populations for the pet trade and conservation efforts around the globe. This article covers basic chelonian reproductive anatomy and physiology, natural history, behavior, and sexing chelonians, in addition to discussing reproductive disorders that are commonly seen by veterinarians. Reproductive disorders covered include infertility, dystocia, follicular stasis, egg yolk coelomitis, phallus prolapse, and reproductive neoplasia. It is hoped that this information will allow clinicians to recognize, understand, and successfully treat reproductive disorders in chelonians, thus providing the best available care for our chelonian patients.