THREE CASES OF CLINICAL LEPTOSPIROSIS IN PATAGONIAN MARAS (DOLICHOTIS PATAGONUM).

Rodents are typically viewed as asymptomatic reservoirs for leptospirosis infection, as clinical disease in rodents is rarely described. This report includes three separate cases of leptospirosis in Patagonian maras (Dolichotis patagonum) over a 3-yr period in multiple locations within a single zoo. All three cases presented with varying clinical signs including lethargy, conjunctival hyperemia, hyperbilirubinemia, and presumed renal azotemia. Infection with Leptospira spp. was diagnosed antemortem by PCR on whole blood (n = 1, Case 1) or urine (n = 2, Cases 2 and 3). Leptospira antibody titers measured by serum microagglutination testing (n = 3) were elevated or increased in all three animals over a 1-3-wk period for Leptospira serovars Bratislava and Hardjo (Case 1) and Grippotyphosa (Case 2 and 3). Two of the three animals responded to treatment with penicillin and doxycycline and supportive care, whereas one animal did not respond to treatment. Postmortem findings in this individual included conjunctivitis, chemosis, dehydration, icterus, tricavitary serosanguinous effusions, necrotizing hepatitis, diffuse pulmonary congestion, and edema. Immunohistochemical examination identified scattered Leptospira organisms within hepatocytes and renal tubular epithelial cells. A wild raccoon (Procyon lotor) at the institution tested positive by PCR on kidney tissue for the same Leptospira spp. serovar and was the suspected source of infection. This case series highlights the clinical importance of leptospirosis as a differential for Patagonian maras presenting with lethargy, ocular signs, acute hepatic disease, and azotemia.

ANESTHESIA OF ZOO-MANAGED AFRICAN PAINTED DOGS (LYCAON PICTUS) USING A DEXMEDETOMIDINE-KETAMINEBUTORPHANOL-MIDAZOLAM COMBINATION.

Zoo-managed adult African painted dogs (Lycaon pictus; n = 17) were anesthetized with mean dosages of dexmedetomidine 5 µg/kg, ketamine 1.93 mg/kg, butorphanol 0.2 mg/kg, and midazolam 0.15 mg/kg IM. Times to induction milestones (mean ± SD or median [range]) were initial effects at 2 min (1-4 min), recumbency at 3.2 ± 1.1 min, and intubation at 11.6 ± 1.3 min. Two dogs required isoflurane supplementation for intubation. Anesthesia was antagonized with mean dosages of atipamezole 0.05 mg/kg IM, naltrexone 0.2 mg/kg IM, and flumazenil 0.01 mg/kg IV. Times from antagonist administration to recovery milestones were extubation at 3.9 ± 1.5 min, control of head at 7.6 ± 2.5 min, sternal positioning at 8.8 ± 2.3 min, and standing at 12.1 ± 3.5 min. Animals were judged ready for reunification with conspecifics at 41.5 min (28-127 min), and reunification occurred at 62.1 ± 35.2 min. Paired arterial blood gas samples were obtained (n = 13). There was a significant decrease in temperature and blood pressure and increase in pO2, BEecf, and HCO3- (P < 0.05). Decreased respiratory rate with hypercapnia was occasionally observed. This protocol provided consistent anesthesia using a low dose α-2 agonist and permitted quick pack reunification.

Serial ultrasonographic measurements of fetal parameters over three successive pregnancies in a captive Eastern black-and-white colobus monkey (Colobus guereza).

This study provides ultrasonographic fetal growth charts for the Eastern black-and-white colobus monkey (Colobus guereza). Throughout three consecutive gestations (-162 to -2 days to parturition) in a single dam, we opportunistically obtained ultrasonographic measurements for the following parameters: biparietal diameter, head circumference, humerus length, femur length, tibia length, radius length, thoracic width, kidney length, and crown-rump length. Biparietal diameter was the most consistently measured parameter. First detection of fetuses occurred between 96 and 162 days before parturition. This report demonstrates that voluntary transabdominal ultrasound can be well-tolerated in the colobus monkey using operant conditioning. These findings may be useful to assess fetal development and predict parturition dates in the absence of a known conception date in this species.

DEGENERATIVE CARDIAC DISEASE IN TWO SPECIES OF TORTOISE (CHELONOIDIS NIGRA COMPLEX, CENTROCHELYS SULCATA).

Cardiac lesions in tortoises are incompletely described in the literature. This retrospective case series includes 11 cases of degenerative cardiac disease in young tortoises from two species in human care: Galápagos tortoise complex (Chelonoidis nigra complex) (n = 9) and sulcata tortoises (Centrochelys sulcata) (n = 2). Eight tortoises were male, two were female, and sex was undetermined for one individual. The age range at the time of death was 10-32 yr with a mean of 19 yr. The most common clinical signs noted prior to death were peripheral edema, lethargy, and inappetence. Common necropsy findings included generalized edema and pericardial effusion. All cases had ventricular myocardial fibrosis and several cases had epicardial adhesions. Additional common findings included hepatic lesions (hepatic lipidosis, hepatic fibrosis, and hepatitis) and pulmonary lesions (pulmonary edema, pulmonary fibrosis, and pneumocytic hypertrophy). A definitive cause for degenerative cardiac disease was not identified in this case series, but the young age distribution of the tortoises suggests that inappropriate environmental parameters, husbandry, and diet should be investigated as possible underlying contributing factors.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Left displacement of the abomasum in a reticulated giraffe bull in managed care.

A 10-y-old giraffe (Giraffa camelopardalis reticulata) bull developed colic after a 3-mo history of reduced feed consumption. Physical examination and management were performed with 2 standing sedations. The giraffe developed metabolic alkalosis and progressive pre-renal azotemia followed by compensatory respiratory acidosis and paradoxical aciduria. A metallic "ping" sound was auscultated on the left side near ribs 10-12. The giraffe was euthanized given the grave prognosis, and postmortem examination confirmed left displacement of the abomasum (LDA) with fluid sequestration (150-190 L [40-50 gal]) within the rumen. Dental disease was evident at postmortem examination and perimortem skull computed tomography. To ensure cases of LDA are not overlooked, the position of the abomasum must be noted during postmortem examination prior to removal of the gastrointestinal tract. The risk factors for the development of LDA in giraffes are not known, and associations such as those of dairy cattle (hypocalcemia, high-concentrate low-fiber diet, and indoor housing) remain to be elucidated.

PRESUMPTIVE CONGENITAL HYPOTHYROIDISM IN RED PANDAS (AILURUS FULGENS FULGENS) FROM FOUR SUCCESSIVE LITTERS.

High neonatal mortality among red pandas (Ailurus fulgens) challenges the long-term sustainability of the Species Survival Plan population. Congenital hypothyroidism (CH) is a rare condition in domestic animals, typically due to an inherited genetic defect. Nongoitrous CH was presumptively diagnosed in 75% (n = 6/8) of red panda neonates from four successive litters, with a common sire and two closely related dams. Antemortem diagnosis of CH was made in three cubs (n = 3/6) based on elevated thyroid stimulating hormone and decreased free thyroxine and total thyroxine levels. Affected cubs also had suggestive clinical signs, which included delayed growth with cretinous dwarf appearance, atonic bladder, delayed gastrointestinal motility, hypercholesterolemia, and hypocalcemia. With sodium levothyroxine therapy, two of the three cubs developed into normal adult red pandas in terms of body size, appearance, and behavior. On necropsy cubs (n = 4) were small with varying degrees of cretin dwarf appearance and hypoplastic thyroids with reduced to no colloid in follicles. These cases demonstrate the importance of collecting thyroid tissue, (or proximal trachea/larynx if gross visualization not possible), in neonates for histopathology. Further investigation into the role of thyroid disease in neonatal red panda mortality is warranted.

Atypical Brucella inopinata-Like Species in 2 Marine Toads.

We describe the isolation of atypical Brucella inopinata-like species and unique clinicopathologic findings in 2 adult marine toads (Rhinella marina), including oophoritis in 1 toad. These findings represent a novel emerging disease in toads and a possible zoonotic pathogen.

Eastern Equine Encephalitis Virus in Mexican Wolf Pups at Zoo, Michigan, USA.

During the 2019 Eastern equine encephalitis virus (EEEV) outbreak in Michigan, two 2-month old Mexican wolf pups experienced neurologic signs, lymphohistiocytic neutrophilic meningoencephalitis with neuronal necrosis and neuronophagia, and acute death. We identified EEEV by reverse transcription real-time PCR and in situ hybridization. Vector mosquitoes were trapped at the zoo.

VALIDATION OF CHEMILUMINESCENT ASSAY FOR CANINE THYROID STIMULATING HORMONE IN RED PANDAS (AILURUS FULGENS FULGENS).

Thyroid abnormalities have been anecdotally reported in red pandas (Ailurus fulgens fulgens); however, definitive diagnosis is hampered by a lack of established reference ranges and validated diagnostic tests. The chemiluminescent assay for canine thyroid stimulating hormone (cTSH) has been validated for use in domestic canids and felids. This study aims to validate the cTSH assay for use in red pandas. Validation was performed via serial dilutions of banked serum samples (n = 15) and both inter- and intra-assay testing. High estimated recoveries and low coefficients of variability indicate that the cTSH assay accurately and consistently measures TSH concentrations in red panda serum. Further studies to generate red panda age and sex TSH reference ranges are indicated.

Epitheliotropic T-cell lymphoma in 2 half-sibling bontebok.

We diagnosed epitheliotropic T-cell lymphoma of the forestomachs in 2 aged, half-sibling, zoo-managed bontebok (Damaliscus pygargus pygargus). One bontebok also had mesenteric lymph node and cutaneous involvement. Both animals had a history of chronic abdominal distension and diminished body condition that resulted in euthanasia. At autopsy, both animals had marked ruminal distension with diffusely blunted ruminal papillae and reticular crests. In case 1, there was an increased amount and particle length of the ruminoreticular fibrous material with scant fluid, and a 2-cm diameter focus of cutaneous crusting adjacent to a mammary teat. In case 2, the rumen and reticulum were fluid-distended with decreased fibrous material. Histologically in case 1, the rumen, reticulum, omasum, and skin had intraepithelial nests and sheets of neoplastic small lymphocytes; in case 2, the rumen and reticulum had a similar neoplastic cell population. Immunohistochemically, neoplastic lymphocytes were immunoreactive for CD3 and negative for CD20, confirming the diagnosis of epitheliotropic T-cell lymphoma.

Successful Return to Active Duty after First Rib Resection for Thoracic Outlet Syndrome.

BACKGROUND: The optimal surgical approach and treatment algorithm for thoracic outlet syndrome (TOS) remain controversial. We sought to examine the outcomes of patients treated at a military medical treatment facility (MTF) for TOS. METHODS: A retrospective review was performed on all patients who had a first rib resection (FRR) for TOS over a 9-year period at a single MTF. Patient demographics, perioperative details, and patient outcomes were examined. Active duty (AD) status and return to AD were reviewed. RESULTS: From 2008 to 2016, 33 FRRs were performed in 32 patients. Of these, 30 patients were on AD with a mean age of 27 years (range, 19-44). The 29 male and 4 female patients were treated for symptoms of venous (23), neurogenic (6), or arterial (4) TOS. The mean time from onset of symptoms was 11 months (range, 1 to 120). The FRR was performed via a transaxillary (13), supraclavicular (12), or paraclavicular (8) approach. Of 21 AD patients with venous TOS, 16 (76%) underwent preoperative thrombolysis. A postoperative venogram or ultrasound was performed in 20 patients, documenting vein patency in 18 (90%). Nine patients underwent subsequent venoplasty or stent placement. Most patients (15) were placed on anticoagulation for 1-6 months. Two AD patients had perioperative complications including a lymph leak and brachial plexus palsy. Twenty-four (89%) patients returned to AD status. One recruit never returned to AD after successful FRR, and two other patients did not return for medical reasons unrelated to the FRR. CONCLUSIONS: Despite a variety of surgical approaches and often delayed presentation, we identified a high percentage of postoperative vein patency and return to AD status in our population. The debate over surgical approach remains; however, a multimodal approach individualized to the patient's presentation and meticulous surgical technique led to successful outcomes in our healthy military population.

VALIDATION OF IMMUNOCRIT AS A DIAGNOSTIC TEST TO DETECT FAILURE OF PASSIVE TRANSFER OF IMMUNITY IN HAND-REARED NONDOMESTIC RUMINANT NEONATES.

Domestic and nondomestic ruminant neonates with failure of passive transfer of immunity (FPI) have an increased risk of morbidity and mortality. Hand-reared individuals often have a higher incidence of FPI compared with those that are dam-reared. Hand-reared, nondomestic ruminant neonates raised at zoological establishments are often fed a commercially available bovine colostrum replacer. Consequently, it is desirable to monitor for FPI using a single test that performs well across a wide range of species. The immunocrit test method has been reported to have acceptable diagnostic sensitivity for detecting FPI in dairy calves. Advantages of the immunocrit are that it is inexpensive, quick, easy to perform, non-species-specific, and only precipitates immunoglobulins. This study evaluated the ability of immunocrit to predict serum immunoglobulin levels and FPI via comparison with radial immunodiffusion (reference method). The study used 100 serum samples collected from hand-reared ruminant neonates from 29 nondomestic species, 12-120 hr old, that were fed a commercial bovine colostrum replacer at a zoological institution. Sensitivity, specificity, and likelihood ratios for FPI were determined using receiver operating characteristic (ROC) curves. The immunocrit cutoff point of 14% maximized sensitivity at 88.6% (95% CI, 78.7-94.9%) and specificity at 83.3% (95% CI, 65.3-94.4%). The area under the ROC curve was 0.92 (95% CI, 0.87-0.98; P < 0.001). This research demonstrates that the immunocrit test has acceptable performance in detecting FPI in a wide variety of nondomestic hand-reared ruminant neonates. Use of the immunocrit test will help improve the identification of FPI neonates and aid in the management of colostrum feeding practices of nondomestic ruminant species in captivity.

Successful chemical ablation of an intraorbital cyst caused by an eyelid injury and iatrogenic ankyloblepharon formation in a duck.

CASE DESCRIPTION A client-owned 2-year-old 1.8-kg (4-lb) male pet Rouen duck (Anas platyrhynchos domesticus) was evaluated because of severe swelling around the left eye following traumatic injury to the upper and lower eyelids and 2 associated surgeries that resulted in the removal of the entire upper and lower eyelid margins. CLINICAL FINDINGS At initial evaluation, ankyloblepharon of the left eye was observed, with no upper or lower eyelid margins and a large, round, fluctuant subcutaneous mass over the left orbit. Orbital exploration and histologic examination revealed a benign cyst consisting of fibrous tissue, conjunctiva, and skeletal muscle bundles. Bacterial culture of cystic fluid yielded few Staphylococcus delphini. TREATMENT AND OUTCOME Excision of the cyst and evisceration of the left globe were performed, and once daily treatment with orally administered enrofloxacin suspension (12.6 mg/kg [5.7 mg/lb]) and meloxicam (1 mg/kg [0.45 mg/lb]) was initiated. Over the next 4 days, the cyst redeveloped and progressively enlarged. Accumulated fluid was aspirated from the cyst, and 20 mg of gentamicin was injected intraorbitally with ultrasound guidance. Over the subsequent 27-month period, no recurrence of clinical signs or adverse effects were reported by the owner. CLINICAL RELEVANCE To the authors' knowledge, this is the first report of cyst formation after adnexal injury and evisceration in birds and its successful treatment with intralesional gentamicin injection. Findings emphasized the importance of preserving lacrimal puncta during adnexal or eye removal surgeries in birds. Intralesional injection of gentamicin with the goal of destroying fluid-producing cells may be a safe and effective way to treat intraorbital cysts in birds and other species, although additional research would be required to confirm this.

The Multi-Axial Failure Response of Porcine Trabecular Skull Bone Estimated Using Microstructural Simulations.

The development of a multi-axial failure criterion for trabecular skull bone has many clinical and biological implications. This failure criterion would allow for modeling of bone under daily loading scenarios that typically are multi-axial in nature. Some yield criteria have been developed to evaluate the failure of trabecular bone, but there is a little consensus among them. To help gain deeper understanding of multi-axial failure response of trabecular skull bone, we developed 30 microstructural finite element models of porous porcine skull bone and subjected them to multi-axial displacement loading simulations that spanned three-dimensional (3D) stress and strain space. High-resolution microcomputed tomography (microCT) scans of porcine trabecular bone were obtained and used to develop the meshes used for finite element simulations. In total, 376 unique multi-axial loading cases were simulated for each of the 30 microstructure models. Then, results from the total of 11,280 simulations (approximately 135,360 central processing unit-hours) were used to develop a mathematical expression, which describes the average three-dimensional yield surface in strain space. Our results indicate that the yield strain of porcine trabecular bone under multi-axial loading is nearly isotropic and despite a spread of yielding points between the 30 different microstructures, no significant relationship between the yield strain and bone volume fraction is observed. The proposed yield equation has simple format and it can be implemented into a macroscopic model for the prediction of failure of whole bones.

DIAGNOSIS AND TREATMENT OF A UNILATERAL RENAL CYSTADENOMA IN AN AFRICAN LION (PANTHERA LEO).

A renal tubular cystadenoma was diagnosed in a 14-yr-old male African lion (Panthera leo). During a routine health evaluation, a left renal mass was identified via physical examination, radiographs, and abdominal ultrasonography. The mass was 30 × 15 cm in size and had a thin capsule with central hypoechoic fluid, suggestive of a perirenal cyst. An exploratory celiotomy with partial nephrectomy was performed without complications. Histologically, the tumor was characterized by a thick fibrous capsule surrounding multiple, variable-sized cysts that markedly compressed the adjacent fibrotic and atrophied renal cortex. Immunohistochemical labeling for Aquaporin-1 and Tamm-Horsfall protein was consistent with a renal tubular cystadenoma of proximal tubule origin. Renal cystadenomas are an uncommon benign epithelial neoplasm. There are only two documented case reports in domestic cats. This report represents the first documentation, to the authors' knowledge, of a renal cystadenoma in a lion.

Evaluation of the immunocrit method to detect failure of passively acquired immunity in dairy calves.

OBJECTIVE To evaluate the usefulness of serum immunocrit measurement to detect failure of passively acquired immunity (FPI) in dairy calves. DESIGN Diagnostic test evaluation. ANIMALS 249 female dairy calves (age, 2 to 6 days). PROCEDURES A blood sample was collected from each calf, and serum was harvested. Immunocrit was measured in serum samples by use of 55% ammonium sulfate solution and the standard technique. Serum IgG concentration was measured by means of radial immunodiffusion (reference standard), with FPI defined as a result < 1,000 mg/dL. The immunocrit value (cutpoint) that maximized both sensitivity and specificity of the method for detection of FPI was determined by construction of receiver operating characteristic curves, and likelihood ratios for positive and negative test results were calculated. RESULTS Immunocrit values were significantly correlated (ρ = 0.71) with serum IgG concentration as measured by radial immunodiffusion. An immunocrit cutpoint of 11% was optimal for detection of FPI in the calves. Sensitivity and specificity of the immunocrit method at this cutpoint were 0.88 (95% confidence interval [CI], 0.79 to 0.97) and 0.51 (95% CI, 0.44 to 0.58), respectively. Likelihood ratios for positive and negative test results were 1.80 (95% CI, 1.51 to 2.14) and 0.23 (95% CI, 0.11 to 0.51), respectively. CONCLUSIONS AND CLINICAL RELEVANCE The immunocrit method was useful for identifying dairy calves with FPI and was simple and could be quickly performed. Because precipitation of immunoglobulins by ammonium sulfate is not species specific, the immunocrit method should be evaluated for detection of FPI in other veterinary species as well.

OBSTETRICAL AND POSTPARTUM COMPLICATIONS IN LESSER MADAGASCAR HEDGEHOG TENRECS (ECHINOPS TELFAIRI): FOUR CASES.

Currently, little is known about diseases and health concerns in tenrecs, family Tenrecidae. During the past 10 yr of breeding lesser Madagascar hedgehog tenrecs ( Echinops telfairi ) at a single zoological institution, a diverse range of obstetric and postpartum complications have been observed: pyometra, metritis, retained fetal membranes, retained fetus, perinatal mortality, and maternal neglect with subsequent successful hand-rearing of neonates. Treatment of these problems is complicated in tenrecs because of their small size and secretive behavior. Some of the cases reported in this article had successful resolution by ovariohysterectomy or cesarean section. The four cases described in this report overall help to disseminate options and outcomes for the diagnosis, treatment, and management of obstetric and postpartum complications in this small, secretive, nondomestic species.

Biomechanical Evaluations of Ocular Injury Risk for Blast Loading.

Ocular trauma is one of the most common types of combat injuries resulting from the exposure of military personnel with improvised explosive devices. The injury mechanism associated with the primary blast wave is poorly understood. We employed a three-dimensional computational model, which included the main internal ocular structures of the eye, spatially varying thickness of the cornea-scleral shell, and nonlinear tissue properties, to calculate the intraocular pressure and stress state of the eye wall and internal ocular structure caused by the blast. The intraocular pressure and stress magnitudes were applied to estimate the injury risk using existing models for blunt impact and blast loading. The simulation results demonstrated that blast loading can induce significant stresses in the different components of the eyes that correlate with observed primary blast injuries in animal studies. Different injury models produced widely different injury risk predictions, which highlights the need for experimental studies evaluating mechanical and functional damage to the ocular structures caused by the blast loading.