Left medial liver lobe torsion and postoperative acute gastric rupture in a 2.5-year-old male-castrated Flemish Giant rabbit (Oryctolagus cuniculus).

A 2.5-year-old male-castrated rabbit presented with acute abdominal pain, lethargy, and anorexia. Digital radiography revealed increased left-sided hepatomegaly, gastric dilation, and decreased peritoneal serosal detail. Abdominal ultrasonography identified a torsed left liver lobe, gastric dilation, and peritoneal effusion. Surgery confirmed a left medial liver lobe torsion, with subsequent lobectomy and seven days of hospitalization. The patient re-presented 2 days after discharge and suddenly died while hospitalized, with acute gastric rupture, fulminant peritonitis, and multifocal hepatic infarcts diagnosed on necropsy. We believe this is the first recorded imaging diagnosis of a left medial liver lobe torsion in a rabbit.

Congenital glaucoma in a tiger (Panthera tigris).

OBJECTIVE: To describe a case of congenital glaucoma in atiger (Panthera tigris). ANIMAL STUDIED: An 8-month-old intact female tiger wasreferred for suspected glaucoma of the right eye. The right eye was buphthalmicwith moderate episcleral injection, circumferential superficial cornealneovascularization, moderate corneal edema, and a fixed dilated pupil. Tapetalreflection was absent due to a mature cataract. Rebound tonometry under generalanesthesia revealed 70 mmHg and 21 mmHg in the right and left eye, respectively. PROCEDURE: A trans-conjunctival enucleation was performedand the globe was submitted for histopathology. RESULTS: Histopathology revealed a thin sclera, amorphousmaterial contouring an imperforate and hypoplastic iridocorneal angle, ahypoplastic lens with severe anterior-posterior compression, subcapsularepithelial hyperplasia, and Morganian globules, and segmental moderate retinalatrophy. Periodic acid-Schiff stain highlighted segmental dilations of theDescemet's membrane. Masson trichrome stain highlighted a pre-irido collagenmembrane. CONCLUSION: The tiger's age and histopathologic findingsare consistent with congenital goniodysgenesis. This is the first known reportof congenital glaucoma in a tiger.

Aquatic bird bornavirus 1 infection in a captive Emu (Dromaius novaehollandiae): presumed natural transmission from free-ranging wild waterfowl.

An adult female emu (Dromaius novaehollandiae) presented with anorexia, maldigestion, weight loss, and various subtle nervous deficits. After four months of unrewarding diagnostics, treatments, and supportive care, the emu was euthanized due to lack of clinical improvement and progressive weight loss. Gross pathology revealed a very narrow pylorus and multiple flaccid diverticula of the small intestines. Histopathological findings included severe lymphoplasmacytic encephalomyelitis and multifocal lymphocytic neuritis associated with the gastrointestinal tract. Immunohistochemistry and polymerase chain reaction on the brain were positive for an avian bornavirus (ABV), and partial sequencing of the matrix gene identified aquatic bird bornavirus-1 (ABBV-1), 100% identical to viruses circulating in wild Canada geese (Branta canadensis). As wild geese frequently grazed and defaecated in the emu's outdoor exhibit, natural transmission of ABBV-1 from free-ranging waterfowl to the emu was presumed to have occurred.

ECHINOCOCCUS EQUINUS HYDATID CYST IN THE LIVER OF A PRZEWALSKI'S HORSE ( EQUUS PRZEWALSKII) IN A CANADIAN ZOO.

A 23-yr-old captive-born Przewalski's horse mare ( Equus przewalskii) was euthanized at a Canadian zoo because of severe colic resulting from rupture of a jejunal pseudodiverticulum. An incidental finding of an encysted larval cestode within a hepatic granuloma was diagnosed on histopathology. Gel-based polymerase chain reaction (PCR) on liver tissue was positive for Echinococcus granulosus sensu lato, and deoxyribonucleic acid sequencing of the PCR product was 100% homologous with Echinococcus equinus. This appears to be the first molecular confirmation of E. equinus in North America, and the first report of cystic echinococcosis in a Przewalski's horse.

SUCCESSFUL TREATMENT OF DIGITAL OSTEITIS BY INTRAVENOUS REGIONAL PERFUSION OF CEFTIOFUR IN AN AFRICAN ELEPHANT (LOXODONTA AFRICANA).

A 41-yr-old African elephant ( Loxodonta africana ) presented with a swollen third digit of the left forelimb and a 2-cm hole in the pad. Corrective trimming, topical treatments, and an oral antibiotic resulted in apparent resolution; however, it reoccurred after 4 mo. Radiographs suggested bone lysis in the third phalanx, with the primary differential diagnosis being septic osteitis. Flushing with metronidazole solution and intravenous regional perfusion (IVRP) of the foot were commenced. A tourniquet was applied just above the carpus, an interdigital vein was identified by ultrasound, and into this vein 2 g (20 ml) of ceftiofur sodium solution, followed by 60 ml of heparinized saline, was administered. The foot was kept raised for 25 min and then the tourniquet was removed. IVRP was repeated every other day for 70 treatments over 6 mo. Healing occurred, which was confirmed radiographically. IVRP offers an excellent treatment modality in a well-trained elephant.

Serum and hepatic vitamin A levels in captive and wild marine toads (Bufo marinus).

The captive breeding program for the endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been hampered by an undiagnosed condition called "Brown Skin Disease" (BSD). Toads develop widespread skin darkening, skin thickening and abnormal shedding and eventually succumb to a chronic loss of viability. This project evaluated the marine toad (Bufo marinus) as a model for the PRCT, examining vitamin A deficiency as a potential cause of BSD. Wild caught marine toads had significantly higher liver vitamin A concentrations (61.89 ± 63.49 µg/g) than captive born marine toads (0.58 ± 0.59 µg/g); P<0.001). A significant difference in serum vitamin A concentration was found between the captive and wild caught toads (P=0.013) and between the low vitamin A-fed and wild caught toads (P=0.004), when controlling for liver vitamin A concentrations. After captive toads were treated with topical and/or oral vitamin A, their hepatic vitamin A concentrations were similar to those of the wild toads, averaging 48.41 ± 37.03 µg/g. However, plasma vitamin A concentrations pre- and post-vitamin A supplementation did not differ statistically. We concluded that plasma vitamin A concentrations do not provide a linear indication of liver/body vitamin A status, and that both topical and oral supplementation with an oil-based vitamin A formulation can increase liver stores in amphibians. No evidence of BSD or other signs of deficiency were noted in the marine toads, although this feeding trial was relatively short (127 days). To date, clinical, pathological and research findings do not support vitamin A deficiency as a primary factor underlying BSD.

Neoplasia of captive yellow sea horses (Hippocampus kuda) and weedy sea dragons (Phyllopteryx taeniolatus).

Syngnathidae is the family of fish that includes sea horses, pipefish, and sea dragons. To date, only a single publication has described neoplasia in syngnathids, a fibrosarcoma of the brood pouch in an aquarium-reared lined sea horse (Hippocampus erectus). From 1998 until 2010, the Toronto Zoo submitted 172 syngnathids for postmortem; species included the spotted or yellow sea horse (Hippocampus kuda), the pot-bellied sea horse (Hippocampus abdominalis) and the weedy sea dragon (Phyllopteryx taeniolatus). Seven neoplasms and two neoplastic-like lesions were identified from these cases. Under light microscopy, the neoplasms had morphological characteristics of a cardiac rhabdomyosarcoma, renal adenocarcinoma, renal adenoma, renal round cell tumors, which were likely lymphomas, exocrine pancreatic carcinoma, and intestinal carcinoma. Of these neoplasms, four had clear evidence of metastasis: the pancreatic and intestinal carcinomas and both round cell tumors. As syngnathids are highly fastidious animals, they can be difficult to maintain in captivity. In order to improve their husbandry, preventative and palliative care, as well as treatment, it is important to investigate and document the types of diseases affecting syngnathids.

Aural Abscesses in Wild Midland Painted Turtles (Chrysemys picta marginata) Admitted to a Wildlife Hospital in Ontario, Canada, 2011-20.

Between 2011 and 2020, the Ontario Turtle Conservation Centre's veterinary hospital admitted 6,335 turtles of eight different species, with 3,246 being midland painted turtles (Chrysemys picta marginata). At the time of admission from the wild, aural abscesses were present in 26 of the painted turtles (0.8%). Aural abscesses were never observed in juvenile turtles and were not found in any other species of turtle admitted to the hospital. An equal number of males and females were affected. All cases showed signs of chronicity. Abscesses alone did not appear to affect the overall health of turtles regardless of clinical signs. All turtles with abscesses as the sole cause for admission were released after successful treatment.

Sarcomatoid carcinoma in the lung of an Egyptian fruit bat (Rousettus aegyptiacus).

A sarcomatoid carcinoma was diagnosed in the lung of a 10-year-old captive Egyptian fruit bat (Rousettus aegyptiacus). Both carcinomatous and sarcomatous cytologic phenotypes were identified histologically. Cells of both types stained positive for pancytokeratin and S-100. Stromal cells stained positively for muscle actin. No staining for vimentin was noted in either neoplastic or normal internal control tissues. To the authors' knowledge, this is the first report of a pulmonary sarcomatoid carcinoma in a bat, and only the third report of sarcomatoid carcinoma outside the human literature.

Paraparesis in a polar bear (Ursus maritimus) associated with West Nile virus infection.

A polar bear (Ursus maritimus) housed at the Toronto Zoo presented with acute-onset, nonambulatory paraparesis. Physical examination 24 hr after onset was otherwise unremarkable, spinal radiographs looked normal, and blood tests indicated mild dehydration. With continued deterioration in its general condition, euthanasia was elected a day later. Necropsy did not reveal a cause for the major presenting clinical signs. Serum collected at the time of initial examination was positive for West Nile virus (WNV) antibodies in a serum neutralization assay and at the time of euthanasia was positive in both a competitive enzyme-linked immunosorbent assay and in a plaque reduction neutralization assay. The major microscopic finding was a mild-to-moderate nonsuppurative meningoencephalomyelitis. WNV was not detected by immunohistochemistry in brain or spinal cord or by real-time reverse transcription-polymerase chain reaction (RT-PCR) and cell culture of brain and kidney, but it was isolated and identified by RT-PCR in second passage cell culture of spleen. Retrospective immunohistochemistry on spleen revealed rare antigen-positive cells, probably macrophages. Prevention of exposure to potentially WNV-infected mosquitoes or vaccination of captive bears against WNV should be considered.

Biomedical evaluation of free-ranging red ruffed lemurs (Varecia rubra) within the Masoala National Park, Madagascar.

Complete health assessments were performed on 22 adult red ruffed lemurs (Varecia rubra), comprising nine males and 13 females, found within the Masoala National Park in northeast Madagascar. Each animal was anesthetized using tiletamine and zolazepam and underwent a thorough physical examination, including measurement of its weight and vital signs; blood collection for hematology, plasma total protein concentration, serum chemistries, fat-soluble vitamins, trace minerals, assessment of iron metabolism, toxoplasmosis serology, viral serologies, and examination for hemoparasites; fecal collection for bacterial culture and parasite examination; and collection of a representative number of any ectoparasites. Comparison of blood values with those of captive lemurs demonstrated a number of significant differences thought to be associated with physiologic state (e.g., reproductive stage and stress), hydration, and diet. There was no evidence of serious infectious diseases, and hemoparasites were not detected. The enteric flora appeared unremarkable; however, results may have been skewed toward more cold-tolerant bacteria. The fecal parasite burden was low. Lemurostrongylus spp. was identified in two of the lemurs, and there were moderate numbers of Laelapidae mites present on approximately one third of the lemurs. This study demonstrated the substantial amount of data that can be collected from free-ranging populations, considered invaluable in the management of captive populations, in reducing the incidence of captivity-related diseases, and in the risk assessment associated with reintroduction programs.

Comparison of biomedical evaluation for white-fronted brown lemurs (Eulemur fulvus albifrons) from four sites in Madagascar.

Health and nutritional assessments of wildlife are important management tools and can provide a means to evaluate ecosystem health. Such examinations were performed on 37 white-fronted brown lemurs (Eulemur fulvus albifrons) from four sites in Madagascar. Comparison of health parameters between sites revealed statistically significant differences in body weight, body temperature, respiratory rate, hematology parameters (white cell count, hematocrit, segmented neutrophil count, and lymphocyte count), serum chemistry parameters (aspartate aminotransferase, alanine aminotransferase, serum alkaline phosphatase, total protein, albumin, phosphorus, calcium, sodium, chloride, and creatinine phosphokinase), and nutrition parameters (copper, zinc, ferritin, retinol, tocopherol, and 25-hydroxycholecalciferol). Two of 10 lemurs tested were positive for toxoplasmosis; none of 10 were positive for Cryptosporidium or Giardia. Enteric bacteria and endo- and ectoparasites were typical. Statistically different values in hematology and chemistry values probably do not reflect clinically significant differences, whereas nutrition parameter differences are likely related to season, soil, and forage availability.

Mermithid nematode infection in a colony of blue-winged grasshoppers (Tropidacris collaris).

A die-off occurred in a captive colony of blue-winged grasshoppers (Tropidacris collaris) at the Toronto Zoo. One fourth of the colony died within a year due to infection with worms initially mistaken for nematomorphs but later identified as nematodes belonging to the Mermithidae, genus Mermis. Mortality persisted and the grasshopper population dwindled over the following years. Mermithid larvae developed in the hemocoel of the insects until they eventually emerged from a hollowed-out exoskeleton. Circumstantial evidence suggests that the parasites were introduced with raspberry browse that was grown on site and contaminated with mermithid eggs.

De Novo Genome and Transcriptome Assembly of the Canadian Beaver (Castor canadensis).

The Canadian beaver (Castor canadensis) is the largest indigenous rodent in North America. We report a draft annotated assembly of the beaver genome, the first for a large rodent and the first mammalian genome assembled directly from uncorrected and moderate coverage (< 30 ×) long reads generated by single-molecule sequencing. The genome size is 2.7 Gb estimated by k-mer analysis. We assembled the beaver genome using the new Canu assembler optimized for noisy reads. The resulting assembly was refined using Pilon supported by short reads (80 ×) and checked for accuracy by congruency against an independent short read assembly. We scaffolded the assembly using the exon-gene models derived from 9805 full-length open reading frames (FL-ORFs) constructed from the beaver leukocyte and muscle transcriptomes. The final assembly comprised 22,515 contigs with an N50 of 278,680 bp and an N50-scaffold of 317,558 bp. Maximum contig and scaffold lengths were 3.3 and 4.2 Mb, respectively, with a combined scaffold length representing 92% of the estimated genome size. The completeness and accuracy of the scaffold assembly was demonstrated by the precise exon placement for 91.1% of the 9805 assembled FL-ORFs and 83.1% of the BUSCO (Benchmarking Universal Single-Copy Orthologs) gene set used to assess the quality of genome assemblies. Well-represented were genes involved in dentition and enamel deposition, defining characteristics of rodents with which the beaver is well-endowed. The study provides insights for genome assembly and an important genomics resource for Castoridae and rodent evolutionary biology.

XY male pseudohermaphroditism in a captive Arabian oryx (Oryx leucoryx).

A 2-yr-old Arabian oryx (Oryx leucoryx) was presented for evaluation of abnormal genitalia and infantile behavior. The oryx had a penis and a scrotum, but testes were not palpable within the scrotum or inguinal canal. The total serum testosterone for the individual was lower than in age-matched males of the same species. Surgical exploration showed markedly hypoplastic intra-abdominal gonads, which demonstrated both testicular and uterine tissue on histologic examination. After karyotype analysis, the individual was classified as an XY male pseudohermaphrodite. This condition resembles two human intersex syndromes: embryonic testicular regression syndrome and partial gonadal dysgenesis syndrome, which occur in familial lines.

Measurement of glycated hemoglobin percentages for use in the diagnosis and monitoring of diabetes mellitus in nonhuman primates.

OBJECTIVE: To identify a technique for measurement of glycated hemoglobin percentage in blood samples obtained from various species of nonhuman primates (NHPs), to determine whether these percentages varied with respect to glycemic control, and to assess whether this physiologic variable provided a suitable test for diagnosing diabetes mellitus in NHPs. SAMPLE POPULATION: 166 blood samples collected from 121 NHPs comprising 22 species from the Haplorhine and Strepsirhine suborders and including nondiabetic, treated-diabetic, and diabetic animals in 23 zoologic institutions throughout the United States. PROCEDURE: Hemoglobin A1c percentage was measured in 154 samples by use of high-performance liquid chromatography. Total glycated hemoglobin percentage was measured in 159 samples by use of a boronate-affinity chromatographic assay. Glucose concentration was measured in 157 samples with an autochemical analyzer by use of a hexose kinase method. RESULTS: The boronate-affinity chromatographic technique for measurement of total glycated hemoglobin percentage was the most suitable method. Nondiabetic Haplorhines had percentages higher than those in nondiabetic Strepsirhines. In Haplorhines, diabetic animals had percentages higher than those in treated-diabetic animals, which had percentages higher than those in nondiabetic animals. In Strepsirhines, this pattern was less pronounced. CONCLUSIONS AND CLINICAL RELEVANCE: Measurement of total glycated hemoglobin percentage provides useful information for diagnosing diabetes mellitus in Haplorhines and, possibly, in Strepsirhines. Until reference ranges are established for each species, it is recommended that results for samples from NHPs without clinical signs of diabetes mellitus be compared with results of samples collected concomitantly from NHPs with clinical signs of this condition.

Comparison of hematologic and biochemical reference ranges between captive populations of northern bald ibises (Geronticus eremita).

Hematologic and biochemical reference ranges for two captive populations of northern bald ibises (Geronticus eremita) were compared. The first consisted of 11 birds at an in-situ breeding colony in Bireçik, southern Turkey. The second consisted of 27 birds housed at the Durrell Wildlife Conservation Trust in Jersey, British Channel Isles (UK). Blood samples were collected in February 1992 by basilic venipuncture under manual restraint. Bireçik birds had higher packed cell volumes and red blood counts but lower white blood cell and lymphocyte counts than Jersey birds. Bireçik birds also had higher total protein, albumin, total globulin, calcium, phosphorus, blood urea nitrogen, and total bilirubin values; higher albumin to globulin ratios; but lower uric acid values and calcium to phosphorus ratios than Jersey birds. Finally, Bireçik birds had higher lactate dehydrogenase but lower gamma glutamyl transferase values than Jersey birds. Male Jersey birds had higher calcium and alkaline phosphatase values, but lower white blood cell and heterophil counts than female Jersey birds. The apparent differences between the two populations are not thought to be biologically significant and may be related to diet and state of hydration.

A comparison between pre- and posthibernation morphometry, hematology, and blood chemistry in viperid snakes.

Snakes from temperate climates are often made to hibernate in zoos to stimulate reproduction. Unfortunately, deaths have occurred during and after hibernation. This study evaluated the health status, pre- and posthibernation, of 31 adult viperid snakes. It included morphometric measurements, hematology, and blood chemistry. No differences were seen in body weights and weight to length ratios between pre- and posthibernation examinations, suggesting that the overall condition of the snakes did not change. No differences were seen in hematologic and blood chemistry parameters, except that bile acids (3alpha-hydroxybile acids) decreased, the implications of which are unknown. Three individuals had markedly high plasma uric acid levels posthibernation; of these, two individuals died from extensive visceral gout and one recovered with fluid therapy. Viperid snakes should be clinically healthy, well hydrated, and in good body condition when they are put into hibernation. They should be maintained in an environment with sufficient humidity and should have access to water. Blood samples should be collected on arousal for measuring plasma uric acid levels. Changes in morphometry, hematology, and blood chemistry appear to be abnormal and should be investigated thoroughly.

Hydromyelia in a Reeves' muntjac (Muntiacus reevesi).

A 24-day-old, 2.2-kg, female Reeves' muntjac (Muntiacus reevesi) acutely developed left hind limb lameness that resolved with rest and anti-inflammatory drugs but recurred at 8 mo of age. Magnetic resonance imaging (MRI) of the lumbar, sacral, and coccygeal spine revealed a fluid-filled dilatation of the central canal of the spinal cord, which was interpreted as a hydromyelic cyst. Surgical exploration and drainage of the cyst were attempted. Despite initially improved mobility, severe plantar ulceration of both hocks developed. The animal was euthanatized. Gross necropsy of the central nervous system revealed a 1.5-cm-long, mild depression with associated yellowing of the dorsal spinal cord in the lumbosacral region, dilatation of the central spinal canal that extended from the cranial thoracic spinal cord with diameter increasing caudally, and mild herniation of the brainstem at the foramen magnum. Histopathologic lesions of the central nervous system were restricted to the spinal cord, with equivocal enlargement of the fourth ventricle. Pathologic changes included irregular dilatation of the central canal, flattening to the absence of the ependymal cells, spongiosis of the gray matter neuropil, and dystrophic calcification. The gross and histologic findings confirmed the diagnosis of hydromyelia.

Biomedical evaluation of free-ranging ring-tailed lemurs (Lemur catta) in Tsimanampetsotsa Strict Nature Reserve, Madagascar.

Complete health assessments were performed on 20 adult ring-tailed lemurs (Lemur catta), 10 males and 10 females, free ranging within the Tsimanampetsotsa Strict Nature Reserve in southwest Madagascar. Each animal was anesthetized using tiletamine and zolazepam, weighed, and given a thorough physical examination. Blood was collected for hematology, determination of plasma total protein concentration, serum chemistry, determination of fat-soluble vitamin and trace mineral concentrations, assessment of iron metabolism, toxoplasmosis and viral serologies, and examination for parasites. Feces were collected for bacterial culture and parasite examination, and representative numbers of ectoparasites were collected. Blood values differed significantly in a number of ways from values in captive lemurs, possibly associated with recent food consumption, hydration, and diet. There was no evidence of serious infectious disease and no hemoparasites. The enteric flora appeared unremarkable, although results may have been skewed toward cold-tolerant bacteria. The fecal parasite burden was low, but there were large numbers of ectoparasites (mites) present. Our study demonstrated that a substantial amount of data can be collected from free-ranging populations, information that is invaluable in the management of captive populations, particularly with regard to disease, and in assessing risks associated with reintroduction programs.