PHARMACOKINETICS OF TRAMADOL AND O-DESMETHYLTRAMADOL IN GIANT TORTOISES (CHELONOIDIS VANDENBURGHI, CHELONOIDIS VICINA).

The objective of this study was to determine the pharmacokinetics of two orally administered doses of tramadol (1 mg/kg and 5 mg/kg) and its metabolite, O-desmethyltramadol (M1) in giant tortoises (Chelonoidis vandenburghi, Chelonoidis vicina). Eleven giant tortoises (C. vandenburghi, C. vicina) received two randomly assigned, oral doses of tramadol (either 1 mg/kg or 5 mg/kg), with a washout period of 3 wk between each dose. The half-life (t½) of orally administered tramadol at 1 mg/kg and 5 mg/kg was 11.9 ± 4.6 h and 13.2 ± 6.1 h, respectively. After oral administration of tramadol at 1 mg/kg and 5 mg/kg, the maximum concentration (Cmax) was 125 ± 69 ng/ml and 518 ± 411 ng/ml, respectively. There were not enough data points to determine pharmacokinetic (PK) parameters for the M1 metabolite from either dose. Tramadol administered orally to giant tortoises at both doses provided measurable plasma concentrations of tramadol for approximately 48 h with occasional transient sedation. Oral tramadol at 5 mg/kg, on average, achieves concentrations of >100 ng/ml, the reported human therapeutic threshold, for 24 h. Based on the low levels of M1 seen in this study, M1 may not be a major metabolite in this taxon.

COMPARISON OF PROTEIN ELECTROPHORESIS AND BIOCHEMICAL ANALYSIS FOR THE QUANTIFICATION OF PLASMA ALBUMIN IN HEALTHY BEARDED DRAGONS (POGONA VITTICEPS).

While electrophoresis is considered the standard method for evaluation of protein concentrations as a result of its direct measurement, albumin is often quantified with biochemical assays. Many laboratory-based chemistry analyzers and clinic-based point-of-care analyzers use the dye bromocresol green (BCG) for the quantitation of albumin. Several studies have shown that albumin concentrations obtained by the standard (BCG) dye-binding method are significantly different from those obtained by protein electrophoresis in avian species and chelonia. The goal of this study was to compare plasma albumin concentrations obtained by the BCG method with those derived from electrophoresis in bearded dragons (Pogona vitticeps). Thirty-six heparinized plasma samples were obtained from 13 clinically healthy male bearded dragons. Albumin was quantified by protein electrophoresis and by the BCG dye-binding method. The two methods were significantly different (P < 0.0001, paired t-test; P < 0.0001, Wilcoxon signed-rank test), with the BCG measurement always equal to or higher than the electrophoretic result. The measurements from both methods were significantly correlated (r = 0.8634, P < 0.0001), but concordance between the two techniques was poor. The Bland-Altman plot appeared to show a greater difference between the two measurements with lower albumin values and lesser difference with higher values. These results indicate that bearded dragon plasma albumin concentration measurements obtained by the BCG dye-binding method are unreliable when compared to those obtained with electrophoresis, suggesting that albumin should be measured by protein electrophoresis for health assessment in bearded dragons.

NEOPLASIA IN SNAKES AT ZOO ATLANTA DURING 1992-2012.

A retrospective study was conducted to review neoplasia of captive snakes in the Zoo Atlanta collection from 1992 to 2012. Of 255 snakes that underwent necropsy and histopathologic examination at Zoo Atlanta during the study period, 37 were observed with neoplasia at necropsy. In those 37 snakes, 42 neoplastic lesions of 18 primary cell types were diagnosed. Thirty-five of those neoplasms (83.3%) were malignant, and of those, 19 were of mesenchymal origin, whereas 14 were of epithelial origin. The median annual rate of neoplasia at necropsy was 12.5% (interquartile range = 2.8-19.5%) over the 21-yr study period. The mean estimated age at death for snakes with neoplasia was 13.2 yr (range, 1-24 yr). Investigating the incidence and clinical significance of neoplasia in captive snakes is vital for developing effective preventative and treatment regimes.

EFFECTS OF A LIGHT-EMITTING DIODE ON THE PRODUCTION OF CHOLECALCIFEROL AND ASSOCIATED BLOOD PARAMETERS IN THE BEARDED DRAGON ( POGONA VITTICEPS).

The importance of vitamin D3 has been documented in multiple reptile species, with deficiencies resulting in alterations in calcium homeostasis, including nutritional secondary hyperparathyroidism. Though vitamin D3 can be obtained directly from dietary sources or from photobiosynthetic production, species variability in diet and behavior makes exposure to ultraviolet B (UVB) radiation an essential requirement for some diurnal species. The effect of different bulbs to promote synthesis of cholecalciferol (vitamin D3) in the bearded dragon ( Pogona vitticeps) was evaluated. Individual animals ( n = 5 for each group) were exposed to industry standard fluorescent bulbs (UVB), non-UVB producing bulbs (UVBN), and light-emitting diode (LED) UVB (LED) bulbs for a period of 11 mo. Weekly measurements of UV index (UVI) were recorded for each bulb. Plasma vitamin D3, 25-hydroxycholecalciferol (25OHD3), ionized calcium (iCa), total calcium (TCa), and phosphorus (P) were measured at time zero and at 4 mo, 8 mo, and 11 mo. Parameters were measured between groups and time points. There were decreases ( P < 0.05) with time for iCa for the LED and UVB groups, for TCa in the UVB group, and for vitamin D3 in the LED and UVBN groups. There were no significant differences between study groups for vitamin D3, iCa, TCa, or P. Overall plasma concentration for 25OHD3 in the LED group was greater than for the UVB ( P = 0.0347) and the UVBN ( P = 0.0490) groups.

Optimal husbandry of hatchling Eastern Indigo Snakes (Drymarchon couperi) during a captive head-start program.

Optimal husbandry techniques are desirable for any headstart program, but frequently are unknown for rare species. Here we describe key reproductive variables and determine optimal incubation temperature and diet diversity for Eastern Indigo Snakes (Drymarchon couperi) grown in laboratory settings. Optimal incubation temperature was estimated from two variables dependent on temperature, shell dimpling, a surrogate for death from fungal infection, and deviation of an egg from an ovoid shape, a surrogate for death from developmental anomalies. Based on these relationships and size at hatching we determined optimal incubation temperature to be 26°C. Additionally, we used incubation data to assess the effect of temperature on duration of incubation and size of hatchlings. We also examined hatchling diets necessary to achieve optimal growth over a 21-month period. These snakes exhibited a positive linear relationship between total mass eaten and growth rate, when individuals were fed less than 1711 g of prey, and displayed constant growth for individuals exceeding 1711 g of prey. Similarly, growth rate increased linearly with increasing diet diversity up to a moderately diverse diet, followed by constant growth for higher levels of diet diversity. Of the two components of diet diversity, diet evenness played a stronger role than diet richness in explaining variance in hatchling growth. These patterns document that our goal of satiating snakes was achieved for some individuals but not others and that diets in which total grams consumed over the first 21 months of life is distributed equivalently among at least three prey genera yielded the fastest growth rates for hatchling snakes.

Nutrition and health in amphibian husbandry.

Amphibian biology is intricate, and there are many inter-related factors that need to be understood before establishing successful Conservation Breeding Programs (CBPs). Nutritional needs of amphibians are highly integrated with disease and their husbandry needs, and the diversity of developmental stages, natural habitats, and feeding strategies result in many different recommendations for proper care and feeding. This review identifies several areas where there is substantial room for improvement in maintaining healthy ex situ amphibian populations specifically in the areas of obtaining and utilizing natural history data for both amphibians and their dietary items, achieving more appropriate environmental parameters, understanding stress and hormone production, and promoting better physical and population health. Using a scientific or research framework to answer questions about disease, nutrition, husbandry, genetics, and endocrinology of ex situ amphibians will improve specialists' understanding of the needs of these species. In general, there is a lack of baseline data and comparative information for most basic aspects of amphibian biology as well as standardized laboratory approaches. Instituting a formalized research approach in multiple scientific disciplines will be beneficial not only to the management of current ex situ populations, but also in moving forward with future conservation and reintroduction projects. This overview of gaps in knowledge concerning ex situ amphibian care should serve as a foundation for much needed future research in these areas.

Exotic venomous snakebite drill.

BACKGROUND: There were 900 exotic venomous snakebites reported from 2000 to 2009. The Association of Zoos and Aquariums' recommends institutions housing venomous reptiles have protocols for appropriate and timely transport of envenomed individuals to hospitals. The study objective was to evaluate functional aspects and potential problems of our emergency operation procedure designed for handling the response to an exotic venomous snakebite during implementation via a simulated drill. The emergency operation procedure consists of two protocols, the protocol for zoo personnel and exotic snakebite protocol for hospital personnel. METHODS: Before the exercise the poison center (PC), zoo, Emergency Medical Services (EMS), receiving hospital emergency department (ED), and pharmacy were contacted. The emergency operation procedure was reviewed to determine areas of deficiency. A checklist of all required actions for each participating institution was created for use during the exercise. The exercise was divided into four phases: zoo, EMS, PC, and ED. Each phase was evaluated by an independent observer. RESULTS: Review of the emergency operation procedure revealed sufficient and easy to follow information for zoo personnel. However, the exotic snakebite protocol for hospital personnel lacked details regarding signs and symptoms expected from each exotic venomous species in the zoo; and indications, dosing, and instructions on reconstitution for each of the antivenom carried by the zoo. Zoo, EMS, ED, and PC personnel completed 95%, 90%, 83%, and 25% of the required tasks, respectively. The PC encountered problems communicating the exotic snakebite protocol for hospital personnel to the ED due to phone and fax equipment failures. Creative solutions to the PC system issues were not identified in a timely manner. Despite the shortcomings, the time from simulated envenomation to antivenom (AV) administration was under an hour. CONCLUSIONS: This drill identified several issues leading to revision of our exotic snakebite protocol for hospital personnel. We also identified suboptimal PC response in the application of the emergency operation procedure. We encourage every poison center in cooperation with local zoos to perform a similar exercise.

The reptilian thyroid and parathyroid glands.

The field of reptilian clinical endocrinology is still in its infancy. The thyroid and parathyroid glands are intimately involved with many basic metabolic functions. These glands have been the subject of extensive research studies in reptilian species; however, the effects of abnormal gland function have been poorly documented in clinical cases. These glands play a major role in maintaining physiologic homeostasis in all vertebrates. With the advent of more sensitive assays, it should be possible to measure the small amounts of hormones found in reptilian species. The purpose of this article is to review the literature regarding clinical endocrinology of the thyroid and parathyroid glands in reptiles.

Baylisascaris procyonis infection in a Moluccan cockatoo (Cacatua moluccensis).

An adult female Moluccan cockatoo (Cacatua moluccensis) was evaluated for a 10-day history of progressive ataxia and weakness. The bird had been exposed intermittently over a 3-day period to a cage that had previously housed juvenile raccoons. Results of diagnostic tests were inconclusive and, despite supportive care, the bird died 7 days after the initial presentation. Histopathologic examination revealed a single nematode larva in the midbrain that was consistent with Baylisascaris species and multifocal granulomas in the left ventricle of the heart. The neurologic disease in this bird was attributed to encephalitis caused by neural larval migration of the raccoon roundworm, Baylisascaris procyonis.

Intrahepatic portosystemic venous shunt in a neonatal roan antelope (Hippotragus equinus cottoni).

A 6-day-old, female roan antelope (Hippotragus equinus cottoni) was diagnosed with a single intrahepatic portosystemic venous shunt at necropsy. Clinical signs had included weakness, lethargy, hypothermia, diarrhea, and a weak suckle response. Multiple seizure episodes were associated with hypoglycemia and characterized by vocalization, muscle fasciculations, and disorientation. Hematologic abnormalities included anemia with hypochromasia, anisocytosis, poikilocytosis, and leukopenia with neutropenia and lymphopenia. Serum biochemical abnormalities included elevations in blood urea nitrogen and total serum bile acid concentration. A portosystemic vascular anomaly should be a differential diagnosis for nonthriving, exotic ruminant calves with overt or subtle neurologic signs, persistent hypoglycemia, and/or elevated bile acids. In very young calves, total bile acid concentration may be more useful in establishing a diagnosis than blood ammonia concentration.

Use of an ELISA for detection of antibody responses in Argentine boa constrictors (Boa constrictor occidentalis).

OBJECTIVE: To develop mouse monoclonal and rabbit polyclonal antibodies against immunoglobulin of Argentine boa constrictors and to demonstrate the ability of these reagents to detect antibody responses in boa constrictors by use of an ELISA and western blot analysis. ANIMALS: Two 3-year-old Argentine boa constrictors. Procedure-Boa constrictors were immunized with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA). Each snake received biweekly inoculations of 250 microg of DNP-BSA (half SC, half IP) for a total of 6 inoculations followed by monthly inoculations for 3 months. Preimmune blood samples were collected. Subsequently, blood was collected immediately prior to each booster inoculation. Anti-DNP antibodies were isolated from immune plasma samples by affinity chromatography. Affinity-purified boa anti-DNP immunoglobulin was used for production of polyclonal and monoclonal antibodies. An ELISA and western blot analysis were used to monitor immune responses, for purification of boa anti-DNP immunoglobulin, and for assessment of polyclonal and monoclonal antibody specificity. RESULTS: A 6-fold increase in optical density (OD405) of immune boa plasma, compared with preimmune plasma, was detected by the polyclonal antibody, and a 12- and 15-fold increase was detected by monoclonal antibodies HL1787 and HL1785, respectively, between weeks 4 and 8. Results of western blot analysis confirmed anti-DNP antibody activity in immunized boa plasma and in affinity column eluates. Polyclonal and monoclonal antibodies detected specific anti-DNP antibody responses in immunized boas. CONCLUSIONS AND CLINICAL RELEVANCE: Polyclonal and monoclonal antibodies recognized boa constrictor immunoglobulin. These antibodies may be useful in serologic tests to determine exposure of snakes to pathogens.

An epizootic of chronic regurgitation associated with chlamydophilosis in recently imported emerald tree boas (Corallus caninus).

One hundred and five wild-caught emerald tree boas (Corallus caninus) were added to a collection of 15 others. in Central Florida, during a 4-mo period. Eighty-one boas (67%) developed repetitive regurgitation during the 23-mo period after the initial introduction, and 61 (75%) of these died. Regurgitation occurred 3-4 days after feeding. Prevalence of regurgitation in this population of snakes was 25%/mo (range 0-42%), and incidence was 3.52/mo (range 0-13/mo). The cumulative mortality for those boas developing repetitive regurgitation (61 of 120) during the 23-mo epizootic was 51%. Hematologic findings included anemia and leukocytosis, with lymphocytosis, monocytosis, and azurophilia. Histologic evaluation of the gastrointestinal tract showed multifocal to diffuse lymphoplasmacytic inflammation with granuloma formation and positive immunohistochemical staining for chlamydial antigen. Electron microscopic evaluation of granulomas showed organisms consistent with Chlamydophila sp.

Ivermectin toxicosis after topical administration in dog-faced fruit bats (Cynopterus brachyotis).

Forty dog-faced fruit bats (Cynopterus brachyotis) were administered 1 drop of 1% ivermectin topically as part of a routine physical exam and deworming program, and 11 developed sudden generalized paresis. Six of the bats recovered within 24-48 hr, and the remaining 5 were presented recumbent and weak to the University of Florida Veterinary Medical Teaching Hospital. Ivermectin toxicosis was suspected, and the admitted bats died or were euthanatized within 3-5 days of the development of clinical signs despite supportive care. Three of the dead bats had renal tubular necrosis.

Nasopharyngeal myxosarcoma in a Bengal tiger (Panthera tigris).

An 18- to 25-yr-old intact female Bengal tiger (Panthera tigris) was diagnosed antemortem and postmortem with nasopharyngeal myxosarcoma metastatic to the lung, chronic lymphoplasmacytic otitis media, and lymphoplasmacytic and eosinophilic stomatitis. Myxosarcomas are rare in domestic animals and seldom metastasize; this tumor has not been previously reported in an exotic felid. Computed tomography of the skull was used during the diagnoses.