Physiologic responses of Cownose Rays following freshwater dips for treatment of capsalid monogeneans.

OBJECTIVE: Two Cownose Rays Rhinoptera bonasus were presented for management of a severe capsalid monogenean infection Benedeniella posterocolpa in a mixed species habitat at an aquarium. METHODS: A series of freshwater (FW) dips were elected to mitigate parasite resistance to praziquantel due to the endemic monogenean population in the system. A pretreatment blood sample was opportunistically obtained, and subsequent samples were processed due to development of clinical signs. RESULT: While the first FW dip was tolerated well and did not induce abnormal behavior, the second led to one individual presenting with tachypnea, pallor, and lethargy. Marked hematological abnormalities requiring medical intervention occurred in both individuals after the second dip. After treatment with elasmobranch Ringer's fluid therapy, sodium bicarbonate, prednisolone acetate, and vitamin E/selenium in the more severely affected ray, and elasmobranch Ringer's alone in the second ray, hematologic derangements and symptoms resolved. Hemoconcentration, hyperproteinemia, hyperlactatemia, and hyperglycemia were attributed to a stress response. A selective loss of urea after exposure to FW resulted in decreased plasma osmolality. CONCLUSION: Given the severity of the stress response and associated complications observed, hyposalinity treatments should be utilized with caution in this species. If this therapy is employed, the clinician is advised to be prepared to administer supportive care coinciding with the FW dip if necessary.

BARIUM SULFATE GELATIN AS A NOVEL APPROACH TO FACILITATE GASTROINTESTINAL TRACT POSITIVE CONTRAST STUDIES IN A CAPTIVE HARBOR SEAL (PHOCA VITULINA) AND CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS) WITHOUT RESTRAINT.

Gastrointestinal tract contrast medium studies are a valuable diagnostic modality to evaluate gastrointestinal anatomy, motility, and pathology. Four positive contrast medium studies were performed twice on a harbor seal (Phoca vitulina) and once each on two California sea lions (Zalophus californianus) to evaluate for gastrointestinal abnormalities by using barium-impregnated gelatin. Because marine mammals in human care routinely receive plain gelatin as a component of their diet and as secondary reinforcement, feeding a barium gelatin mitigates the need for tube feeding or restraint. Operant conditioning was used to position the pinnipeds for voluntary radiographs. The barium gelatin permitted adequate evaluation of gastric emptying and intestinal transit times and good evaluation of the structure of the intestinal tract. Full evaluation of gastric anatomy was limited due to the gelatin blocks not conforming to the stomach in their solid form and the barium quickly exiting the stomach as barium gelatin blocks disintegrated and because orthogonal views could not always be acquired. Even with these limitations, barium gelatin resulted in diagnostically valuable contrast imaging in a stress-free patient setting with reduced risk of aspiration and eliminated the effects that anesthesia can have on gastric motility as well as other anesthesia-associated risks.

RETROSPECTIVE REVIEW OF PROPOFOL ANESTHESIA IN MULTIPLE ELASMOBRANCH SPECIES AT GEORGIA AQUARIUM, 2010-2022.

General anesthesia is often required in elasmobranch species for medical procedures. A variety of anesthetic drugs have been administered to elasmobranchs with wide variability in efficacy and safety. A retrospective review of 47 anesthetic procedures using IV propofol in eight different elasmobranch species at the Georgia Aquarium from 2010 to 2022 was performed. Cases involving seven sand tiger sharks (Carcharias taurus), four largetooth sawfish (Pristis perotteti), one longcomb sawfish (Pristis zijsron), four blacktip reef sharks (Carcharhinus melanopterus), three silvertip sharks (Carcharhinus albimarginatus), one sandbar shark (Carcharhinus plumbeus), five cownose rays (Rhinoptera bonasus), and one blotched fantail stingray (Taeniura meyeni) were evaluated. Induction dose of IV propofol (median: 2.5; 25-75%: 2.3-3.0; range: 1.7-4.0 mg/kg), time to desired effect (median: 4.0; 25-75%: 2.0-5.0; range: 0.5-15.0 min) and anesthetic duration (median: 76.0; 25-75%: 61.5-119.0; range: 27-216 min) were reported in all species. In six procedures (12.7%), maintenance of desired anesthetic plane required a supplemental dose of propofol IV (1 mg/kg) or addition of tricaine methanesulfonate (70 mg/L) as an immersion bath. The most common side effects were apnea and prolonged recovery. The IV propofol was efficacious and provided a procedural plane of anesthesia for a clinically relevant period of time in the majority of elasmobranch species, but observation for and management of complications is warranted.

A novel herpes-like virus inducing branchial lesions in a tiger shark (Galeocerdo cuvier).

A juvenile, male tiger shark (Galeocerdo cuvier) developed illness after capture in Florida waters and was euthanized. Gross lesions included mild skin abrasions, hepatic atrophy, and coelomic fluid. Histologically, gills contained multifocal lamellar epithelial cell necrosis and thromboses. Scattered gill and esophageal epithelial cells had large, basophilic, intracytoplasmic, and intranuclear inclusions. Ultrastructurally, lamellar epithelial cells contained arrays of intracytoplasmic viral particles and scattered intranuclear nucleocapsids. Capsulated virions were 148 ± 11 nm with an 84 ± 8 nm icosahedral nucleocapsid and an electron-dense core. Next-generation sequencing, quantitative polymerase chain reaction, and in situ hybridization performed on formalin-fixed tissue confirmed a herpes-like viral infection. The viral polymerase shared 24% to 31% protein homology with other alloherpesviruses of fish, indicating a divergent virus. This report documents the pathologic findings associated with a molecularly confirmed novel herpes-like virus in an elasmobranch.

Baseline Health and Nutritional Parameters of Wild Sand Tigers Sampled in Delaware Bay.

Species-specific hematological reference values are essential for diagnosis and treatment of disease and maintaining overall health of animals. This information is lacking for many species of elasmobranchs maintained in zoos and aquaria, thus reducing the effectiveness of care for these animals. Descriptive statistics and reference intervals were calculated for hematocrit and complete blood cell counts, biochemistry and protein electrophoresis parameters, trace minerals, vitamins, heavy metals, reproductive hormones, and fatty acids in the blood of 153 wild Sand Tigers Carcharias taurus of both sexes and a range of sizes caught in Delaware Bay (Delaware, USA). Mean hematocrit, total white blood cell counts, lymphocyte differentials, glucose, phosphorus, amylase, and aspartate aminotransferase levels were significantly higher in juveniles than in adults. Levels of estradiol, progesterone, testosterone, and differences in selenium and eicosapentaenoic acid (a polyunsaturated fatty acid) between males and females suggest that they are important parameters for improving Sand Tiger breeding success in managed care. Finally, blood metal levels for arsenic, cadmium, lead, and mercury suggest low levels of contaminant exposure for Sand Tigers during their summer residence in Delaware Bay. The results of this study provide baseline health parameters for wild Sand Tigers that will aid in effective maintenance of aquarium animals and contribute to a greater understanding of the biology of these sharks and efforts to accomplish sustainable management of their populations.

PHARMACOKINETIC BEHAVIOR OF MELOXICAM IN LOGGERHEAD (CARETTA CARETTA), KEMP'S RIDLEY (LEPIDOCHELYS KEMPII), AND GREEN (CHELONIA MYDAS) SEA TURTLES AFTER SUBCUTANEOUS ADMINISTRATION.

The objective of this study was to determine the pharmacokinetics of a single dose of meloxicam administered subcutaneously (SQ) to three species of sea turtles: loggerheads (Caretta caretta), Kemp's ridley (Lepidochelys kempii), and greens (Chelonia mydas). A dose of 1 mg/kg was given to the Kemp's ridleys and greens, whereas the loggerheads received 2 mg/kg. After SQ administration, the half-life (t1/2) of meloxicam administered at 1 mg/kg in the Kemp's ridleys was 5.51 hr but could not be determined in the greens. The half-life of meloxicam administered at 2 mg/kg in the loggerheads was 2.99 hr. The maximum concentration (Cmax) for meloxicam after SQ administration at 1 mg/kg in the Kemp's ridleys was 6.76 µg/ml and in the greens was 9.35 µg/ml. The Cmax in loggerheads for meloxicam after SQ administration at 2 mg/kg was 3.63 µg/mL. Meloxicam administered SQ at a dose of 1 mg/kg to the Kemp's ridley and greens provided measurable plasma concentrations of meloxicam for 48 and 120 hr, respectively, with no adverse side effects. In loggerheads, meloxicam administered SQ at a dose of 2 mg/kg provided measurable plasma levels of meloxicam for only 24 hr. Plasma levels of meloxicam of greater than 0.5 µg/ml are considered to be therapeutic in humans. Results suggested that administration of meloxicam SQ at 1 mg/kg in Kemp's ridleys and greens would result in plasma concentrations greater than 0.5 µg/ml for 12 and 120 hr, respectively. The administration of 2 mg/kg meloxicam to loggerhead turtles resulted in plasma concentrations greater than 0.5 µg/ml for only 4 hr.

Testosterone and semen seasonality for the sand tiger shark Carcharias taurus†.

Understanding the fundamental reproductive biology of a species is the first step toward identifying parameters that are critical for reproduction and for the development of assisted reproductive techniques. Ejaculates were collected from aquarium (n = 24) and in situ (n = 34) sand tiger sharks Carcharias taurus. Volume, pH, osmolarity, sperm concentration, motility, status, morphology, and plasma membrane integrity were assessed for each ejaculate. Semen with the highest proportion of motile sperm was collected between April and June for both in situ and aquarium sand tiger sharks indicating a seasonal reproductive cycle. Overall, 17 of 30 semen samples collected from aquarium sharks from April through June contained motile sperm compared to 29 of 29 of in situ sharks, demonstrating semen quality differences between aquarium and in situ sharks. Sperm motility, status, morphology, and plasma membrane integrity were significantly higher (P < 0.05) for in situ compared to aquarium sand tiger sharks. Testosterone was measured by an enzyme immunoassay validated for the species. Testosterone concentration was seasonal for both aquarium and in situ sharks with highest concentrations measured in spring and lowest in summer. In situ sharks had higher (P < 0.05) testosterone concentration in spring than aquarium sharks. This study demonstrated annual reproduction with spring seasonality for male sand tiger sharks through marked seasonal differences in testosterone and semen production. Lower testosterone and poorer semen quality was observed in aquarium sharks likely contributing to the species' limited reproductive success in aquariums.

Primary intracranial fibrosarcoma in a southern sea otter Enhydra lutris nereis.

Southern sea otters Enhydra lutris nereis, a threatened marine mammal species, face numerous environmental and infectious disease challenges in their native habitat of coastal California, USA. However, there are few published cases describing neoplasia in sea otters despite their relatively long life span when cared for in aquarium settings. An 18 yr old neutered male southern sea otter, born and raised in human care, presented with an acute onset of seizures and dull mentation. Magnetic resonance imaging of the head revealed a large, central brain lesion. After no improvement with treatment, euthanasia was elected due to a poor prognosis. Grossly, a poorly demarcated, granular, tan mass expanded the cranial meninges in the longitudinal fissure at the level of the cruciate sulcus and extended into the underlying gray matter and superficial white matter. Histologically, the mass was composed of spindle cells, forming haphazardly arranged interlacing bundles and herringbone patterns, with a high mitotic count, moderate cellular pleomorphism, and prominent vascularization. Neoplastic cells demonstrated positive immunoreactivity for vimentin and negative immunoreactivity for smooth muscle actin, factor VIII-related antigen, S100, melan-A, E-cadherin, desmin, glial fibrillary acidic protein, and cytokeratin AE1/AE3. Based on gross, histologic, and immunohistochemical findings, the mass was most consistent with a primary intracranial fibrosarcoma (PIF). PIFs are a rare neoplasm in both humans and other animals with few reports in the veterinary literature. This is the first recorded case of a PIF in a sea otter.

Natural environmental conditions and collaborative efforts provide the secret to success for sand tiger shark Carcharias taurus reproduction in aquaria.

Sand tiger sharks are an iconic large shark species held in aquaria worldwide. They rarely reproduce under managed care, with only seven aquaria reporting limited and sporadic success. For the first time in the Americas, a full-term young was born in an aquarium. The young was the result of breeding among a group of sharks purposefully brought together in 2016 for reproduction. Sharks were maintained in natural seawater and exposed to natural light and seasonal temperature fluctuations similar to their in situ counterparts. Decreased food consumption associated with breeding season and gestation was observed. Gestation time estimated from breeding observations and parturition was 321 days. Although the neonate was stillborn, this was a significant achievement. The husbandry details described within will be useful for other aquaria striving to support the reproduction of sand tiger sharks.

Evaluation of a genus-specific ELISA and a commercial Aspergillus Western blot IgG® immunoblot kit for the diagnosis of aspergillosis in common bottlenose dolphins (Tursiops truncatus).

Aspergillosis is a fungal infection with high mortality and morbidity rates. As in humans, its definitive diagnosis is difficult in animals, and thus new laboratory tools are required to overcome the diagnostic limitations due to low specificity and lack of standardization. In this study of common bottlenose dolphins (Tursiops truncatus), we evaluated the diagnostic performance of a new commercial immunoblot kit that had been initially developed for the serologic diagnosis of chronic aspergillosis in humans. Using this in a quantitative approach, we first established its positive cutoff within an observation cohort of 32 serum samples from dolphins with "proven" or "probable" diagnosis of aspergillosis and 55 negative controls. A novel enzyme-linked immunosorbent assay (ELISA) test was also developed for detecting anti-Aspergillus antibodies, and results were compared between the two assays. Overall, the diagnostic performance of immunoblot and ELISA were strongly correlated (P < .0001). The former showed lower sensitivity (65.6% versus 90.6%), but higher specificity (92.7% vs. 69.1%), with no cross-reaction with other fungal infections caused by miscellaneous non-Aspergillus genera. When assessing their use in a validation cohort, the immunoblot kit and the ELISA enabled positive diagnosis before mycological cultures in 42.9% and 33.3% subjects addressed for suspicion of aspergillosis, respectively. There was also significant impact of antifungal treatment on the results of the two tests (P < .05). In all, these new serological methods show promise in aiding in the diagnosis of aspergillosis in dolphins, and illustrate the opportunity to adapt commercial reagents directed for human diagnostics to detect similar changes in other animals.

WHOLE BLOOD TRANSFUSIONS TO TREAT SEVERE ANEMIA IN SEVEN COWNOSE RAYS ( RHINOPTERA BONASUS) AND ONE SHORT-TAIL STINGRAY ( DASYATIS BREVICAUDATA).

Blood transfusions can provide life-saving treatment to severely anemic animals. Due to limited availability and the difficulty of storing whole blood and blood products, such as fresh frozen plasma and packed red blood cells, exotic animals often receive fresh whole blood transfusions. Little is known about elasmobranch blood types and transfusions. Conspecific cross-matches within several different elasmobranch species were negative, indicating that in an emergency situation a single whole blood transfusion may be possible without causing a transfusion reaction. Experimental transfusions between healthy conspecific Atlantic rays ( Dasyatis sabina) showed no adverse reactions and autotransfusions in marbled electric rays ( Torpedo marmorata) were successful. There are no published reports of blood transfusions performed on clinically abnormal elasmobranchs. The following case series documents blood transfusions performed on seven cownose rays ( Rhinoptera bonasus) and one short-tail stingray ( Dasyatis brevicaudata). All rays were treated with the same protocol, which included pretreatment with steroids and antibiotics followed by an intravenous transfusion of freshly collected, heparinized, whole blood. Three animals survived and currently exhibit no abnormal clinical signs. Two animals died 55 days and 100 days post transfusion. Three animals died 2-22 days post transfusion. Although complications from blood transfusions could not be ruled out, all five animals that died had other health problems that likely contributed to their demise. All eight animals would almost certainly have died without a blood transfusion as they were severely anemic and moribund at the time of presentation. The methods described in this paper may be useful in the treatment of severely anemic elasmobranchs and this is the first report of blood transfusions in clinically abnormal elasmobranchs.

MEDICAL MANAGEMENT OF COELOMIC DISTENTION, ABNORMAL SWIMMING, SUBSTRATE RETENTION, AND HEMATOLOGIC CHANGES IN A REEF MANTA RAY (MANTA ALFREDI).

An adult, female, reef manta ray (Manta alfredi) was evaluated for abnormal swimming and coelomic distention after colliding with a floating dock in an exhibit. Initial clinical signs included abnormal posture and swimming. Clinical signs progressed to include muscle wasting, poor body condition, and coelomic distention. Further diagnostics revealed excessive exhibit substrate within the gastrointestinal tract, gastric ulcers, free coelomic fluid, possible spinal lesion, possible uterine abnormality, and hematologic changes. The ray was treated with repeated gastroscopic examinations to remove substrate from the stomach. Psyllium and mineral oil were administered in gel food to assist with passage of substrate through the gastrointestinal tract. Gastric ulcers were treated with sucralfate. Vitamin B complex, iron dextran, and Yunnan Paiyao were used to treat the anemia. Amikacin and sulfadimethoxine-ormetoprim were administered for suspected bacterial and coccidial infections, respectively. Over the course of 11 mo the ray returned to normal health.

COMPARISON OF PRE- AND POSTQUARANTINE BLOOD CHEMISTRY AND HEMATOLOGY VALUES FROM WILD-CAUGHT COWNOSE RAYS (RHINOPTERA BONASUS).

Though one of the most widely kept elasmobranchs in human care, the cownose ray (CNR; Rhinoptera bonasus ), remains a species with minimal published information on hematologic reference intervals. As part of a larger study investigating the health and nutrition of the CNR, this study established a preliminary data set of plasma chemistry and hematology values specific to animals recently caught from the wild and compared this data set (intake sample) to values obtained following a period of quarantine (27-40 days) in an aquarium (exit sample). Blood samples were collected from 47 wild female (n = 46) and male (n = 1) CNR caught in pound nets off the coast of North Carolina and South Carolina. Differences between intake and exit values were analyzed. Due to the preponderance of female animals, data were not analyzed for sex differences. Plasma biochemical profiles were performed and analyzed. A select number of complete blood cell counts were performed (n = 24 from 12 animals). Statistically significant differences (P < 0.05) specific to time of sampling were determined for packed cell volume, total solids, blood urea nitrogen, sodium, chloride, potassium, phosphorus, cholesterol, glucose, and aspartate aminotransferase. Values reported are a significant expansion on the existing limited data for CNRs and will serve as a reference for health assessment of individuals both in the wild and in exhibit populations.

PLASMA PROTEIN ELECTROPHORESIS AND SELECT ACUTE PHASE PROTEINS IN HEALTHY BONNETHEAD SHARKS (SPHYRNA TIBURO) UNDER MANAGED CARE.

Preventative health care of elasmobranchs is an important but understudied field of aquatic veterinary medicine. Evaluation of inflammation through the acute phase response is a valuable tool in health assessments. To better assess the health of bonnethead sharks ( Sphyrna tiburo ) under managed care, normal reference intervals of protein electrophoresis (EPH) and the acute phase proteins, C-reactive protein (CRP) and haptoglobin (HP), were established. Blood was collected from wild caught, captive raised bonnethead sharks housed at public aquaria. Lithium heparinized plasma was either submitted fresh or stored at -80°C prior to submission. Electrophoresis identified protein fractions with migration characteristics similar to other animals with albumin, α-1 globulin, α-2 globulin, ß globulin, and γ globulin. These fractions were classified as fractions 1-5 as fractional contents are unknown in this species. Commercial reagents for CRP and HP were validated for use in bonnethead sharks. Reference intervals were established using the robust method recommended by the American Society for Veterinary Clinical Pathology for the calculation of 90% reference intervals. Once established, the diagnostic and clinical applicability of these reference intervals was used to assess blood from individuals with known infectious diseases that resulted in systemic inflammation and eventual death. Unhealthy bonnethead sharks had significantly decreased fraction 2, fraction 3, and fraction 3:4 ratio and significantly increased fraction 5, CRP, and HP. These findings advance our understanding of elasmobranch acute phase inflammatory response and health and aid clinicians in the diagnosis of inflammatory disease in bonnethead sharks.

Right Heart Failure in an African Penguin ( Spheniscus demersus ).

A 19-year-old male African penguin ( Spheniscus demersus ) was presented with coelomic distention after a 6-week history of lethargy and decreased appetite. Results of radiographs showed loss of coelomic detail, and ultrasound and computed tomography results revealed coelomic fluid and dilated hepatic veins. Echocardiography revealed moderate right atrial enlargement. Findings were consistent with right-sided cardiac disease. Treatment with furosemide initially reduced ascites, but the clinical condition worsened weeks later and enalapril, pimobendan, and sildenafil were added to the medical therapy. At 12 weeks after presentation, results of an echocardiogram revealed persistent right atrioventricular valve regurgitation, moderate ascites, and dilation of hepatic veins. Clinical signs of right heart failure were managed through adjustments in medical therapy and coelomic fluid aspiration, but the bird died 18 weeks after initial presentation. Gross and microscopic findings were consistent with valvular insufficiency and right-sided heart failure. To our knowledge, this case is the first documented report of cardiac disease in an African penguin.

VORICONAZOLE TOXICITY IN MULTIPLE PENGUIN SPECIES.

Aspergillosis is a common respiratory fungal disease in penguins managed under human care. Triazole antifungal drugs, including itraconazole, are most commonly used for treatment; however, itraconazole treatment failures from drug resistance are becoming more common, requiring newer treatment options. Voriconazole, a newer triazole, is being used more often. Until recently, no voriconazole pharmacokinetic studies had been performed in penguins, leading to empiric dosing based on other avian studies. This has led to increased anecdotal reporting of apparent voriconazole toxicity in penguins. This report describes 18 probable and 6 suspected cases of voriconazole toxicity in six penguin species from nine institutions: 12 African penguins (Spheniscus demersus), 5 Humboldt penguins (Spheniscus humboldti), 3 Magellanic penguins (Spheniscus magellanicus), 2 gentoo penguins (Pygoscelis papua papua), 1 macaroni penguin (Eudyptes chrysolophus), and 1 emperor penguin (Aptenodytes forsteri). Observed clinical signs of toxicity included anorexia, lethargy, weakness, ataxia, paresis, apparent vision changes, seizure-like activity, and generalized seizures. Similar signs of toxicity have also been reported in humans, in whom voriconazole therapeutic plasma concentration for Aspergillus spp. infections is 2-6 µg/ml. Plasma voriconazole concentrations were measured in 18 samples from penguins showing clinical signs suggestive of voriconazole toxicity. The concentrations ranged from 8.12 to 64.17 µg/ml, with penguins having plasma concentrations above 30 µg/ml exhibiting moderate to severe neurologic signs, including ataxia, paresis, and seizures. These concentrations were well above those known to result in central nervous system toxicity, including encephalopathy, in humans. This case series highlights the importance of species-specific dosing of voriconazole in penguins and plasma therapeutic drug monitoring. Further investigation, including pharmacokinetic studies, is warranted. The authors recommend caution in determining voriconazole dosages for use in penguin species.

Epitheliocystis hyperinfection in captive spotted eagle rays Aetobatus narinari associated with a novel Chlamydiales 16S rDNA signature sequence.

This report details 2 cases of epitheliocystis in spotted eagle rays Aetobatus narinari associated with a novel Chlamydiales 16S rDNA signature sequence. Epitheliocystis is a common disease of variable severity affecting >50 species of wild and cultured freshwater and marine teleosts. Disease in elasmobranchs is rarely reported and descriptions are limited. Occurring in gill and skin epithelium, lesions are characterized by large hypertrophied cells with basophilic inclusions containing Gram-negative, chlamydia-like bacteria. Acute lethargy, labored respiration, and abnormal swimming developed in a captive spotted eagle ray following an uneventful quarantine period, and mild epitheliocystis lesions were found microscopically. Three months later, a second animal exhibited similar signs. A gill clip revealed myriad spherical bodies identical to the previous case, and treatment with chloramphenicol and oxytetracycline was initiated. Despite therapy, respiration became irregular and euthanasia was elected. Histologically, epitheliocystis inclusions up to 200 µm filled approximately 80% of lamellar troughs. Multifocal mild hypertrophy and hyperplasia of lamellar tips was accompanied by mild to moderate infiltrates of granulocytes and lymphocytes. Electron microscopy revealed a homogeneous population of elongate chlamydia-like bacterial forms similar in size and morphology to the primary long cells described in teleosts. Immunohistochemical staining with a polyclonal anti-chlamydial lipopolysaccharide antibody was positive. Sequence analysis of a unique 296 bp Chlamydiales signature sequence amplicon isolated from the rays showed greatest homology (85 to 87%) to 'Candidatus Piscichlamydia salmonis'.

Retroperitoneal hemangiosarcoma in a common carp Cyprinus carpio: a case report.

A 7.5 kg common carp Cyprinus carpio presented with prominent localized swelling in the caudal right coelomic area, identified by ultrasound as a fluid filled mass. Fine needle aspirate (FNA) and culture results suggested a sterile seroma. Centesis removed 290 ml of serosanguinous fluid that returned within days. Recheck ultrasonography revealed a solid component within the cavity. Radiography demonstrated irregular lysis and misalignment of vertebrae adjacent to the mass, most suggestive of bacterial osteitis or neoplasia. Treatment with antibiotics followed for 2 mo but failed to resolve the lesion. Repeated radiography and ultrasonography showed progressive enlargement of the mass, with vertebral lysis and invasion characteristic of neoplasia. Ultrasound-guided FNA of the solid component of the mass was non-diagnostic. Euthanasia was elected due to the poor clinical response and primary differential of neoplasia. Post-mortem MRI and CT confirmed a retroperitoneal soft tissue mass, partially surrounded by a fluid-filled cavity, causing vertebral lysis and infiltration of the spinal canal. Expansion of the mass caused severe muscle loss and an associated elevation in creatine kinase (>120000 U l-1). Necropsy results corroborated the MRI and CT findings, revealing a retroperitoneal, multilobular, red and tan mass causing dorsal displacement of the vertebral column, with vertebral lysis, pathologic fracture and invasion of the spinal canal. Histopathologic examination revealed a locally aggressive neoplasm exhibiting multiple patterns of growth, including endothelial lined vascular channels and solid areas formed by more pleomorphic polygonal and spindle cells, consistent with hemangiosarcoma.

Modified-closed castration: a novel technique for sea otter (Enhydra lutris nereis) orchiectomies.

A novel surgical technique was used in the routine castrations of two intact male southern sea otters, Enhydra lutris nereis, housed at the Georgia Aquarium (Atlanta, Georgia, USA). This technique involved incising the parietal vaginal tunic to allow placement of double ligation of the ductus deferens, testicular artery, and pampiniform plexus en masse. After ligating and transecting these structures, they were introduced back into the tunic, which was closed with a circumferential ligature. The incision site was closed in a routine manner. Both otters recovered well from the procedure. One otter had mild cutaneous dehiscence postoperatively, and the other had no obvious complications. Benefits of this procedure include reduced risk of ligature slippage or loosening and resultant hemorrhage, as provided by the traditional open portion of the castration, and decreased postoperative swelling, as provided by the closed part of the castration. To the authors' knowledge, this is the first time this technique has been described for use in sea otters.

The microbiome of African penguins (Spheniscus demersus) under managed care resembles that of wild marine mammals and birds.

Animals under managed care in zoos and aquariums are ideal surrogate study subjects for endangered species that are difficult to obtain in the wild. We compared the fecal and oral microbiomes of healthy, managed African penguins (Spheniscus demersus) to those of other domestic and wild vertebrate hosts to determine how host identity, diet, and environment shape the penguin microbiome. The African penguin oral microbiome was more similar to that of piscivorous marine mammals, suggesting that diet and a marine environment together play a strong role in shaping the oral microbiome. Conversely, the penguin cloaca/fecal microbiome was more similar to that of other birds, suggesting that host phylogeny plays a significant role in shaping the gut microbiome. Although the penguins were born under managed care, they had a gut microbiome more similar to that of wild bird species compared to domesticated (factory-farmed) birds, suggesting that the managed care environment and diet resemble those experienced by wild birds. Finally, the microbiome composition at external body sites was broadly similar to that of the habitat, suggesting sharing of microbes between animals and their environment. Future studies should link these results to microbial functional capacity and host health, which will help inform conservation efforts.