Christopher S. Hanley

RENAL EVALUATION IN THE HEALTHY GREEN IGUANA (IGUANA IGUANA): ASSESSMENT OF PLASMA BIOCHEMISTRY, GLOMERULAR FILTRATION RATE, AND ENDOSCOPIC BIOPSY

Abstract Plasma biochemistry, iohexol clearance, endoscopic renal evaluation, and biopsy were performed in 23 clinically healthy 2-yr-old green iguanas (Iguana iguana). Mean (±SD) values for packed cell volume (30 ± 3%), total protein (62 ± 7 g/L, 6.2 ± 0.7 g/dl), albumin (25 ± 2 g/L, 2.5 ± 0.2 g/dl), globulin (37 ± 6 g/L, 3.7 ± 0.6 g/ dl), total calcium (3.0 ± 0.2 mmol/L, 12.0 ± 0.7 mg/dl), ionized calcium (1.38 ± 0.1 mmol/L), phosphorus (1.32 ± 0.28 mmol/L, 4.1 ± 0.9 mg/dl), uric acid (222 ± 100 μmol/L, 3.8 ± 1.7 mg/dl), sodium (148 ± 3 mmol/L or mEq/ L), and potassium (2.6 ± 0.4 mmol/L or mEq/L) were considered within normal limits. Values for urea were low (<1.4 mmol/L, <4 mg/dl) with 70% of samples below the detectable analyzer range. After the i.v. injection of 75 mg/ kg iohexol into the caudal (ventral coccygeal or tail) vein, serial blood collections were performed over 32 hr. Iohexol assays by high-performance liquid chromatography produced plasma iohexol clearance graphs for each lizard. A three-compartment model was used to fit area under the curve values and to obtain the glomerular filtration rate (GFR) using regression analysis. The mean GFR (SD) was 16.56 ± 3.90 ml/kg/hr, with a 95% confidence interval of 14.78–18.34 ml/kg/hr. Bilateral endoscopic renal evaluation and biopsy provided tissue samples of excellent diagnostic quality, which correlated with tissue harvested at necropsy and evaluated histologically. None of the 23 animals demonstrated any adverse effects of iohexol clearance or endoscopy. Recommended diagnostics for the evaluation of renal function and disease in the green iguana include plasma biochemical profiles, iohexol clearance, endoscopic examination, and renal biopsy.

Effects of anesthesia and surgery on serial blood gas values and lactate concentrations in yellow perch (Perca flavescens), walleye pike (Sander vitreus), and koi (Cyprinus carpio).

OBJECTIVE-To evaluate serial blood gas values and lactate concentrations in 3 fish species undergoing surgery and to compare blood lactate concentrations between fish that survived and those that died during the short-term postoperative period. DESIGN-Prospective cohort study. Animals-10 yellow perch, 5 walleye pike, and 8 koi. PROCEDURES-Blood samples were collected from each fish at 3 time points: before anesthesia, during anesthesia, and immediately after surgery. Blood gas values and blood lactate concentrations were measured. Fish were monitored for 2 weeks postoperatively. RESULTS-All walleye and koi survived, but 2 perch died. Blood pH significantly decreased in perch from before to during anesthesia, but increased back to preanesthesia baseline values after surgery. Blood Pco(2) decreased significantly in perch from before anesthesia to immediately after surgery, and also from during anesthesia to immediately after surgery, whereas blood Pco(2) decreased significantly in koi from before to during anesthesia. Blood Po(2) increased significantly in both perch and koi from before to during anesthesia, and also in koi from before anesthesia to immediately after surgery. For all 3 species, blood lactate concentrations increased significantly from before anesthesia to immediately after surgery. Blood lactate concentration (mean +/- SD) immediately after surgery for the 8 surviving perch was 6.06 +/- 1.47 mmol/L, which was significantly lower than blood lactate concentrations in the 2 nonsurviving perch (10.58 and 10.72 mmol/L). CONCLUSIONS AND CLINICAL RELEVANCE-High blood lactate concentrations following surgery in fish may be predictive of a poor short-term postoperative survival rate.

EXERTIONAL MYOPATHY IN WHOOPING CRANES (GRUS AMERICANA) WITH PROGNOSTIC GUIDELINES

Abstract Exertional myopathy developed in three whooping cranes (Grus americana) secondary to routine capture, handling, and trauma. Presumptive diagnosis of exertional myopathy was based on history of recent capture or trauma, clinical signs, and elevation of aspartate aminotransferase, alanine aminotransferase, creatine kinase, lactate dehydrogenase, and serum potassium. Treatments were attempted in each case, but ultimately were not successful. Gross and microscopic lesions at necropsy confirmed the diagnosis in each case, with the leg musculature most severely affected. Guidelines for determining prognosis of exertional myopathy in cranes have been included based on the analysis of these cases and others in the literature. As treatment is largely unrewarding, prevention remains the key in controlling exertional myopathy. Identification of predisposing factors and proper handling, immobilization, and transportation techniques can help prevent development of exertional myopathy in cranes.

COMPARISON OF THE EFFECT OF DIPOTASSIUM ETHYLENEDIAMINETETRAACETIC ACID AND LITHIUM HEPARIN ON HEMATOLOGIC VALUES IN THE GREEN IGUANA (IGUANA IGUANA)

Abstract We compared the effects of dipotassium ethylenediaminetetraacetic acid (EDTA) and lithium heparin on hematologic values of green iguanas (Iguana iguana). Thirty-two privately owned sibling iguanas had blood drawn, and the sample was divided into three components: an EDTA tube, a heparin tube, and a nonanticoagulated blood smear. A full reptilian complete blood count was performed on each anticoagulated sample, and white blood cell (WBC) and leukocyte differential counts were performed on the whole-blood smears. Heparin and EDTA samples differed significantly in absolute values of thrombocytes, WBC, heterophils, and monocytes. The EDTA had no significant effect on the packed cell volume or plasma protein values, and the white blood count and differential counts produced with EDTA were more similar to those of the nonanticoagulated blood smear than were the counts produced with heparin.

Interclavicular Hemangiosarcoma in a Double Yellow-headed Amazon Parrot (Amazona ochrocephala oratrix)

Abstract A 13-year-old female double yellow-headed Amazon parrot (Amazona ochrocephala oratrix) was examined for respiratory distress and partial anorexia. Radiographs, ultrasonography, and computed tomography revealed a soft-tissue opacity in the right cranial coelom with a necrotic or fluid-filled center. Endoscopy was used to visualize the mass, collect diagnostic samples, and treat the patient by cyst ablation and fistula formation. The symptoms returned within weeks after each treatment, and the bird died 36 days after initial presentation. Gross and histopathologic examination revealed the mass was a hemangiosarcoma that was attached to the right internal carotid artery.

Isolation, morphologic, serologic and molecular identification of Acanthamoeba T4 genotype from the liver of a Temminck's tragopan (Tragopan temminckii)

Members of the genus Acanthamoeba are usually free-living amoebae that are found in a variety of ecological niches including soil, fresh and brackish water, dust in the air, heating, ventilating, and air conditioning filters, swimming pools and hot tubs. Occasionally they are also known to cause central nervous system infections in humans and animals. We isolated into culture an amoeba from the liver of a Temmincks tragopan (horned pheasant) (Tragopan temminckii) that died of amoebic infection. We identified the infecting amoeba as Acanthamoeba sp. based on culture characteristics, cyst morphology and immunofluorescence assays. Additionally, we identified the amoeba as Acanthamoeba, genotype T4, by sequencing a diagnostic region of the nuclear small subunit ribosomal RNA gene.

IMMOBILIZATION OF FREE-RANGING HOFFMANN'S TWO-TOED AND BROWN-THROATED THREE-TOED SLOTHS USING KETAMINE AND MEDETOMIDINE: A COMPARASION OF PHYSIOLOGIC PARAMETERS

Free-ranging Hoffmanns two-toed sloths (Choloepus hoffmanni; n=26) and brown-throated three-toed sloths (Bradypus variegatus; nequals;15) were manually captured and immobilized with 2.5 mg/kg ketamine + 0.02 mg/kg medetomidine administered intramuscularly. Physical examinations were conducted on each sloth 10 min after initial injection, and blood, fecal, and ectoparasite samples were collected. Heart rate, respiratory rate, body temperature, indirect systolic blood pressure, and indirect peripheral oxygen saturation were monitored every 5 min for the duration of anesthesia. After 45 min, atipamazole (0.1 mg/kg) was administered intramuscularly, as an antagonist to medetomidine, in order to facilitate recovery. All recoveries were smooth, rapid, and uneventful. Physiologic parameters were compared across time, gender, and species. All sloths, regardless of species and gender, demonstrated a time-dependent decrease in heart rate and blood pressure, and an increase in respiratory rate, during the course of anesthesia. Peripheral oxygen saturation was similar for all sloths over time. There were significant species differences for heart rate (Choloepus > Bradypus), respiratory rate (Choloepus > Bradypus), and systolic blood pressure (Bradypus > Choloepus), while there were significant gender differences for body temperature (males > females) and blood pressure (males > females). Results of this study suggest that the ketamine–medetomidine mixture, as described above, is a safe and effective anesthetic combination in free-ranging two- and three-toed sloths, although peripheral blood pressure should be monitored during anesthesia.

VISCERAL AND PRESUMPTIVE NEURAL BAYLISASCARIASIS IN AN ORANGUTAN (PONGO PYGMAEUS)

Abstract A 32.5-year-old female hybrid orangutan (Pongo pygmaeus) developed hind-limb stiffness that progressed to tetraparesis over 2 wk. Repeated diagnostic evaluations, including serial magnetic resonance imaging of the central nervous system, revealed nonspecific lesions involving both the deep white and gray matter with an intact blood–brain barrier. Multiple empirical treatments failed to produce improvement and the animal was humanely euthanized. Histology of a granuloma in the ileum contained a nematode parasite, most consistent with Baylisascaris procyonis. Additionally, neuropil vacuolization, rarefaction, astrocytic scarring, and an eosinophilic granuloma and lymphoeosinophilic perivascular cuffing in the brain were suggestive of nematode migration. These findings confirm the presence of visceral larval migrans and support the presence of neural larval migrans. This case report of Baylisascaris procyonis confirms the presentation for the first time in an ape and documents the difficulty in antemortem diagnosis of neural larval migrans.

SEROSURVEY OF SELECTED ARBOVIRAL PATHOGENS IN FREE-RANGING, TWO-TOED SLOTHS (CHOLOEPUS HOFFMANNI) AND THREE-TOED SLOTHS (BRADYPUS VARIEGATUS) IN COSTA RICA, 2005-07.

Abstract We screened for antibodies to 16 arboviruses in four populations of free-ranging sloths in Costa Rica. Blood samples were taken from 16 Hoffmans two-toed sloths (HTSs; Choloepus hoffmanni) and 26 brown-throated sloths (BTSs; Bradypus variegatus) over a 3-yr period. We used serologic assays to detect antibodies against 10 arboviruses previously described in sloths (St. Louis encephalitis [SLEV], Changuinola, Venezuelan equine encephalitis, Ilheus [ILHV], Oropouche, Mayaro, Utinga, Murutucu, Punta Toro, and vesicular stomatitis [VSV] viruses) and six arboviruses not described in sloths (Rio Grande, West Nile [WNV], eastern equine encephalitis, Piry, Munguba, and La Crosse viruses). Overall, 80% of sloths had detectable antibodies to SLEV, 67% had antibodies to ILHV, 32% to Punta Toro virus, 30% to Changuinola virus, 15% to WNV, 14% to VSV, 11% to Venezuelan equine encephalitis virus, and 10% to Rio Grande virus. No samples had detectable antibodies to the remaining eight viruses. We found a significant increase in prevalence of antibody to VSV in HTSs between 2005 and 2007, and for WNV antibody between 2005 and 2006. We found no significant differences in the prevalences of antibodies to the sampled viruses between the two locations. Antibody prevalences were significantly higher in HTSs than in BTSs for SLEV in 2005. Antibody-positive results for ILHV were likely due to cross-reaction with SLEV. The novel finding of antibodies to Rio Grande virus in sloths could be due to cross-reaction with another phlebovirus. These findings might have implications for land management and domestic animal health. Due to the nature of the study, we could not determine whether sloths could represent amplification hosts for these viruses, or whether they were only exposed and could be used as sentinel species. Further studies are needed to fully characterize arboviral exposure in sloths.

Surgical Removal of a Thymoma in a Burrowing Owl (Athene cunicularia)

Abstract A 12-year-old male burrowing owl (Athene cunicularia) was presented for evaluation of a mass in the right cervical region. A thymoma was diagnosed after surgical resection and histopathologic evaluation. Extensive adherence of the thymoma to the esophagus and suspected invasion into the right jugular vein contributed to a poor postsurgical outcome. Diagnosis and treatment of thymomas in avian species is similar to that in mammals. Surgical removal of noninvasive thymomas is usually curative. Thymomas are rarely reported in avian species and this is the first report in a strigiform bird.