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.

MINIMALLY INVASIVE SURGICAL REPAIR FOR ABDOMINAL WALL HERNIAS IN NONHUMAN PRIMATES, TWO CASES IN WESTERN LOWLAND GORILLAS (GORILLA GORILLA GORILLA).

A 33-yr-old female Western lowland gorilla (Gorilla gorilla gorilla) was diagnosed with a congenital umbilical hernia that was reducible and asymptomatic; change in the hernia was noted after parturition and concerns regarding increased risk of bowel incarceration developed. The hernia was successfully repaired with robot-assisted laparoscopic surgery. A 5-mon-old male Western lowland gorilla presented with bilateral inguinal hernias that were repaired via elective laparoscopic repair. In both cases, the gorillas did well without complications and never appeared to acknowledge wounds or exhibit signs of pain postoperatively. A literature review and interinstitutional survey was conducted to determine success rate of minimally invasive versus open repair of hernias in nonhuman primates (NHP). Of the cases identified, recurrence and/or wound morbidity was seen in 0% of laparoscopic repairs and 50% of open repairs. NHP may benefit from elective, minimally invasive surgical techniques that may reduce hernia recurrences and wound morbidity.

Bridging the Research Gap between Live Collections in Zoos and Preserved Collections in Natural History Museums.

Zoos and natural history museums are both collections-based institutions with important missions in biodiversity research and education. Animals in zoos are a repository and living record of the world's biodiversity, whereas natural history museums are a permanent historical record of snapshots of biodiversity in time. Surprisingly, despite significant overlap in institutional missions, formal partnerships between these institution types are infrequent. Life history information, pedigrees, and medical records maintained at zoos should be seen as complementary to historical records of morphology, genetics, and distribution kept at museums. Through examining both institution types, we synthesize the benefits and challenges of cross-institutional exchanges and propose actions to increase the dialog between zoos and museums. With a growing recognition of the importance of collections to the advancement of scientific research and discovery, a transformational impact could be made with long-term investments in connecting the institutions that are caretakers of living and preserved animals.

DETERMINATION OF VERTEBRAL HEART SCALE AND ECHOCARDIOGRAPHIC MEASUREMENTS IN HEALTHY ANESTHETIZED AFRICAN WILD DOGS (LYCAON PICTUS) IN HUMAN CARE.

Cardiac disease is an important cause of mortality in African wild dogs in human care. Vertebral heart scale (VHS) is a well-documented objective measure of cardiac size and is commonly used in domestic dogs. The VHS of 63 clinically healthy African wild dogs housed in zoological institutions was retrospectively calculated. Using the robust method of reference interval (RI) calculation, the RI for VHS in captive African wild dogs was 9.3-10.8. Echocardiographic measurements from 16 clinically healthy and 2 African wild dogs with preclinical dilated cardiomyopathy are reported. The cardiac biomarkers N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) were measured in a subset of African wild dogs. The median plasma NT-proBNP measurement was 845 pM/L (range 366-1,388) and the median serum cTnI measurement was 0.02 ng/ml (0.01-0.04). These data can be used for the assessment and identification of cardiac disease in this endangered species.

MYCOTIC PNEUMONIA AND ENCEPHALITIS IN SOUTHERN PUDU (PUDU PUDA).

This case series describes six confirmed cases of mycotic encephalitis and/or mycotic pneumonia in southern pudu (Pudu puda). One case involved a 10.5-yr-old intact female that presented with an inability to stand, eventually progressing to grand mal seizures. Magnetic resonance imaging showed a lesion within the cerebellar vermis with edema causing cerebellar herniation. The animal was euthanized based on a grave prognosis. Gross and histologic examination revealed primary central nervous system phaeohyphomycosis. Curvularia spicifera was sequenced from the cerebellar tissue. This is the first time this fungus has been reported as a primary central nervous system infection in an artiodactyl species. The remaining five cases occurred in neonates between 17 and 67 days old. Clinical signs varied widely, including facial swelling, weakness, posterior paresis, and sudden death. Antifungal therapy was initiated in three neonatal animals but was unsuccessful in each case. All neonates had active mycotic pneumonia caused by Aspergillus fumigatus or Mucor spp. at time of death; four of these animals also had disseminated disease that caused mycotic encephalitis. This case series indicates that fungal disease should be included in the differential diagnosis list of any pudu presenting for neurologic or respiratory clinical signs.

RETROSPECTIVE ANALYSIS AND VALIDATION OF SERUM SYMMETRIC DIMETHYLARGININE (SDMA) CONCENTRATIONS IN CHEETAHS ( ACINONYX JUBATUS).

Kidney disease is common among captive cheetahs ( Acinonyx jubatus). Serum creatinine is the most common measurement to estimate glomerular filtration rate (GFR) because of the ease of its clinical use, but it is a crude estimate that only increases after significant disease is already present and is affected by extrarenal factors. Symmetric dimethylarginine (SDMA) is a renal biomarker in humans, dogs, and cats that correlates with serum creatinine and GFR and appears to be an earlier and more specific biomarker for kidney disease. Ninety-two banked serum samples from 11 cheetahs housed at the Oklahoma City Zoo from 1992 to 2012 were retrospectively analyzed. Histopathology results were available for 10/11 cheetahs, and all 10 had histologic renal lesions. General categories of renal lesions included glomerulosclerosis (7/10; 70%), amyloidosis (7/10; 70%), inflammatory (9/10; 90%), and oxalate nephrosis (2/10; 20%). SDMA immunoassay and mass spectrometry were measured for validation and compared with creatinine to assess for correlation. Serum creatinine concentrations were determined by enzymatic colorimetric methods. SDMA immunoassay was validated in cheetahs and correlated well with serum creatinine ( R2=0.687; P < 0.0001). SDMA and serum creatinine measured from freeze-thawed stored samples show high correlation in individual cheetahs ( R2 = 0.972; P < 0.0001). These data support that SDMA could be a promising renal biomarker in cheetahs. Further research is warranted to investigate whether SDMA might be an earlier indicator of kidney disease in cheetahs and whether this assay can be extended to other nondomestic carnivores.

Management of a Nonhealing, Superficial Corneal Ulcer in a Hyacinth Macaw (Anodorhynchus hyacinthinus).

A 26-year-old, female hyacinth macaw (Anodorhynchus hyacinthinus) was presented for ophthalmology consultation for a history of a chronic, nonhealing corneal ulcer of the right eye. On examination, a 5 × 4-mm axial, superficial corneal ulcer with loose epithelial edges was found. During multiple recheck examinations over 4 months, the ulcer was treated by debridement with a sterile cotton-tipped applicator, diamond burr debridement, diamond burr debridement with cyanoacrylate tissue adhesive, and grid keratotomy with cyanoacrylate tissue adhesive, all performed under anesthesia with eventual resolution of the corneal ulcer.

MANAGEMENT OF PODODERMATITIS WITH AN ORTHOTIC BOOT IN A SOUTHERN ISABELA GIANT TORTOISE (CHELONOIDIS VICINA).

A 62-yr-old male Southern Isabela giant tortoise (Chelonoidis vicina) had a 1-yr history of chronic, reoccurring pododermatitis on the palmar surface of the left forelimb. Aggressive wound management was instituted and included surgical debridement, vacuum-assisted closure, and orthotic boot support during healing. A custom fabricated, carbon fiber clamshell Charcot Restraint Orthotic Walker walking boot was utilized to reduce focal pressure over the wound during weight bearing and promote a more normal gait. Distal padding was used to distribute pressure on the palmar surface of the left forelimb, with a focal depression in the padding preventing pressure directly over the wound. The design and trim lines were adjusted to allow shoulder and elbow motion without impingement. The clamshell design allowed relatively easy removal for wound inspection and dressing changes. The wound ultimately resolved after 9 wk of management with the orthotic boot, with no reoccurrence over the next 3 yr.

ATTEMPTED SURGICAL CORRECTION OF A PERSISTENT RIGHT FOURTH AORTIC ARCH IN A JUVENILE ROTHSCHILD'S GIRAFFE (GIRAFFA CAMELOPARDALIS ROTHSCHILDI).

A 5-mo-old female Rothschild's giraffe ( Giraffa camelopardalis rothschildi) presented for regurgitation. Esophagoscopy at 24 wk of age revealed a markedly dilated cranial esophagus with a tight stricture at the level of the heart base consistent with a vascular ring anomaly. Surgical exploration confirmed persistent right fourth aortic arch with ductus originating from left subclavian artery at its junction with the aorta and left subclavian artery. The patent ductus arteriosus was surgically ligated. The procedure was complicated by limited surgical access and vascular friability resulting in uncontrollable hemorrhage, and the animal was euthanatized. The animal's large size and unique shape precluded preoperative examination by computed tomography. Surgical accessibility was poor because cranial retraction of the thoracic limb was limited. Histology revealed focal degeneration of the aorta and subclavian artery and muscular degeneration of the esophagus. Degeneration was attributed to local hypoxia from compression by the vascular structure as the animal grew.

PHARMACOKINETIC EVALUATION OF A LONG-ACTING FENTANYL SOLUTION AFTER TRANSDERMAL ADMINISTRATION IN HELMETED GUINEAFOWL (NUMIDA MELEAGRIS).

The objective of this study was to investigate the pharmacokinetics of a long-acting fentanyl solution in helmeted guineafowl ( Numida meleagris ) after transdermal administration. Twenty-one guineafowl received a single administration of 5 mg/kg of fentanyl transdermal solution. No adverse effects on behavior were appreciated. Plasma fentanyl concentrations were determined by liquid chromatography-mass spectrometry analysis of protein-precipitated samples. Mean maximum plasma concentration was 228.8 ng/ml at 4 hr. The mean plasma terminal half-life was 33.2 hr. At 168 hr the mean plasma concentration was 1.3 ng/ml. A single topical dose of 5 mg/kg appears to be safe for use in this species and maintained plasma concentrations above those reported to be analgesic in dogs for at least 7 days.

Intraocular pressure in free-ranging anuran species in Oklahoma.

Ocular disease appears to be a common issue in anurans. Intraocular pressures were measured for six species of free-ranging anurans in central Oklahoma. No significant differences were identified between left or right eyes. There was a significant negative relationship between the weight of the anuran and intraocular pressure. The intraocular pressure range for the six species was 3-10 mm Hg. Tonometry values in anurans are, to the authors' knowledge, previously unreported and this study provides initial information on intraocular pressure measurement in anurans.

Pharmacokinetics of selamectin in helmeted guineafowl (Numida meleagris) after topical administration.

Twenty-one healthy helmeted guineafowl (Numida meleagris) housed at the Oklahoma City Zoo were used to evaluate the pharmacokinetic parameters of topical selamectin. Birds were divided randomly into three groups of seven birds each. On day 1, all birds received one dose of 20 mg/kg selamectin topically. Based on the group number, blood was collected from each bird on three separate occasions over a 28-day period. Plasma using liquid chromatography with mass spectrometry was used to determine selamectin concentrations. Mean plasma terminal half-life and maximum plasma concentrations of selamectin were 5.8 days and 16.1 ng/ml, respectively, with maximum plasma levels reached at 3 days. No adverse effects were detected. Birds in this study did reach and maintain plasma levels reported as therapeutic in other species for 19 days. Based on these results, selamectin may be a valuable antiparasiticide in some avian species.

Retroperitoneal abscesses in two western lowland gorillas (Gorilla gorilla gorilla).

This report describes two cases of retroperitoneal abscesses in female western lowland gorillas (Gorilla gorilla gorilla). Clinical symptoms included perivulvar discharge, lameness, hindlimb paresis, and general malaise. Retroperitoneal abscesses should be considered as part of a complete differential list in female gorillas with similar clinical signs.

Persimmon phytobezoars in meerkats (Suricata suricatta).

Two meerkats (Suricata suricatta) died acutely and gastric bezoars were found at necropsy. Four of the eight remaining meerkats had bezoars identified radiographically. Surgical gastrotomies were performed and bezoars containing orange fibrous material were removed. Histologic examination of the bezoars and persimmon fruit from a tree in the exhibit revealed that the materials were identical. Tannins found in ripe persimmons are known to coagulate in the presence of gastric acid, and the resultant phytobezoars can lead to gastrointestinal obstructions. All four meerkats recovered uneventfully. The combination of interspecies aggression and a diet change may have led to consumption of persimmons produced by a tree in the exhibit. Persimmon phytobezoars are also seen in humans and horses.

Primary feather follicle ablation in common pintails (Anas acuta acuta) and a white-faced whistling duck (Dendrocygna viduata).

Eight 1-yr-old common pintails (Anas acuta acuta) and one 2-yr-old white-faced whistling duck (Dendrocygna viduata) were presented for the persistence of primary flight feathers 1 yr after pinioning. The birds were housed outdoors in an open enclosure necessitating flight prevention. The birds were placed under general anesthesia, and a diode laser was used to ablate the primary feather follicles of the previously pinioned wing. Swelling was the most common side effect seen in seven out of nine treated birds. Other side effects included ulceration, hyperemia, edema, and serosanguinous discharge. All side effects were resolved by 12 wk postprocedure. Laser feather follicle ablation was successful in 28 of 40 (70%) of the treated common pintail feathers, and flight was not observed 7 mo following the procedure in any of these birds. Feather follicle ablation was successful in two of six (33%) of the treated white-faced whistling duck feathers, and the bird in question was observed flying 5 mo after the procedure. Primary feather follicle ablation with a diode laser was a successful method of flight prevention in common pintails but was not effective for a white-faced whistling duck.

Comparison of laryngeal mask airway use with endotracheal intubation during anesthesia of western lowland gorillas (Gorilla gorilla gorilla).

The laryngeal mask airway is an alternative to endotracheal intubation that achieves control of the airway by creating a seal around the larynx with an inflatable cuff. This study compared use of the laryngeal mask airway with endotracheal intubation in anesthetized western lowland gorillas (Gorilla gorilla gorilla). Eight adult gorillas were immobilized for routine and diagnostic purposes for a total of nine anesthetic events. During each anesthetic event, gorillas were either intubated (n = 4; group A) or fitted with a laryngeal mask airway (n= 5; group B). Time required to place each airway device, physiologic parameters, and arterial blood gas were measured and compared between the two groups. There were no significant differences between the two groups for time required to place airway device, heart rate, hemoglobin oxygen saturation, end-tidal carbon dioxide, arterial partial pressure of carbon dioxide, or arterial pH between the two groups. Mean arterial partial pressure of oxygen was significantly greater in group B, 15 (group A: 94 +/- 44 mm Hg; group B: 408 +/- 36 mm Hg; P= 0.0025) and 45 (group A: 104 +/- 21 mm Hg; group B: 407 +/- 77 mm Hg; P = 0.0026) min after airway device placement. Mean respiratory rate was significantly greater in group A at multiple time points. Mean arterial pressure (group A: 129 +/- 16 mm Hg; group B: 60 +/- 8 mm Hg) and diastolic blood pressure (group A: 115 +/- 21 mm Hg; group B: 36 +/- 10 mm Hg) were significantly greater in group A at the time of airway device placement. The laryngeal mask airway maintained oxygenation and ventilation effectively in all gorillas and is a useful alternative to endotracheal intubation in western lowland gorillas.

Evaluation of gastroscopic biopsy for diagnosis of Cryptosporidium sp. infection in snakes.

Cryptosporidium sp. is a protozoal parasite that can cause hypertrophic gastritis, regurgitation, and chronic wasting in snakes. Diagnosis can be challenging because of intermittent shedding of the organism in the feces. The purpose of this study was to evaluate gastroscopic biopsy as a diagnostic method for Cryptosporidium sp. screening during an outbreak at the Oklahoma City Zoo. Twenty-two snakes were immobilized by chamber induction with an inhalant anesthetic. Gross lesions were seen in seven snakes and consisted of hyperemia, thickening of the gastric mucosa as observed by lack of rugal folds, and a cobblestoned appearance. Gastric biopsy was performed for histologic evaluation (n = 21). Hypertrophic gastritis with intralesional cryptosporidia was diagnosed in five animals. Eleven animals died or were euthanized and complete necropsy was used to evaluate diagnostic measurements of performance of gastric biopsy. Sensitivity for gastric biopsy was 71.4% and specificity was 100%. Gastroscopy appears to be a useful diagnostic method for Cryptosporidium infection in snakes and can help distinguish true infection from prey-based cryptosporidia seen in fecal samples.

Metastatic ductal adenocarcinoma in a Western Hognose snake (Heterodon nasicus).

A 17-yr-old Western Hognose snake (Heterodon nasicus) presented with a prominent midcoelomic swelling. Surgical exploration revealed a large, multicystic, irregular, tan, and firm mass grossly effacing the splenopancreas. The mass was subsequently removed. Histologically, the mass was composed of tubules of columnar to flattened neoplastic cells with an abundant stroma and moderate cellular atypia consistent with a scirrhous adenocarcinoma, likely ductal in origin, given the location of the neoplastic mass. Bloodwork revealed anemia, monocytosis, marked hypercalcemia, and, postoperatively, persistent hyperglycemia. After postoperative recovery, the snake was diagnosed with iatrogenically induced diabetes mellitus and exocrine pancreatic insufficiency. Due to the inability to clinically control the diabetes mellitus and exocrine pancreatic insufficiency and when additional palpable masses were noted, the snake was euthanatized. Necropsy and histopathologic examination confirmed metastasis of the previously removed adenocarcinoma to the liver, right kidney, and large intestine.

Plasma pharmacokinetics of selamectin after a single topical administration in the American bullfrog (Rana catesbeiana).

Parasitism is common in wild and captive amphibians; however, pharmacologic data are lacking for anthelmintic drugs. This study was developed to determine the plasma pharmacokinetics of selamectin after topical administration in bullfrogs. Thirty-two adult American bullfrogs (Rana catesbeiana) were randomly assigned into eight groups of four with each group representing a different collection time point. Seven groups received selamectin (6 mg/ kg) topically and the remaining group served as the untreated control group. One group of frogs was euthanized and blood samples immediately collected on days 0 (control), 1, 5, 10, 15, 20, 25, and 30. Plasma was analyzed for selamectin using high performance liquid chromatography with fluorescence detection. Individual samples were analyzed, then data were reported as the mean of the four frogs at each time point. A histologic evaluation of the lung, liver, kidney, and skin tissues was performed and none of the frogs showed histologic evidence of toxicity due to selamectin administration. The mean peak plasma concentration was 162.5 +/- 42.3 ng/ml, area under the curve was 2,856 ng day/ml, mean residence time was 12.2 days, and disappearance half-life was 1.87 days. Based on the plasma pharmacokinetics, bullfrogs appear to absorb selamectin very efficiently, concentrations reach high levels in the plasma, and there were no apparent histologic effects from single dose administration.

Acute appendicitis in a chimpanzee (Pan troglodytes).

BACKGROUND: A 7-year old, female chimpanzee (Pan troglodytes) developed acute abdominal pain and anorexia. An irregular, mineral opacity was identified in the caudal right quadrant of the abdomen on radiographs and computed tomography scan, which appeared to be in the region of the cecal appendage. RESULTS AND CONCLUSIONS: A diagnosis of acute appendicitis was made based on clinical signs, abnormal haematology findings, and consultation with a human radiologist. Exploratory laparotomy was performed and the cecal appendage was removed. On histologic examination, the mucosal epithelium contained eosinophilic and neutrophilic inflammation. The inflammation extended through the tunica muscularis to the serosal surface and adjacent mesentery. The histologic findings were consistent with acute appendicitis in humans. The chimpanzee recovered well from surgery with immediate improvement in clinical signs and no post-operative complications.