Diffuse large B cell lymphoma and a novel gammaherpesvirus in northern elephant seals Mirounga angustirostris.

Two emaciated male northern elephant seal (NES) Mirounga angustirostris pups were admitted to The Marine Mammal Center (Sausalito, California, USA) and treated for malnutrition. Complete blood counts showed a progressive moderate to marked leukocytosis characterized by a predominance of large monomorphic mononuclear cells of probable lymphoid origin, frequently with flower-shaped nuclei. Both seals were euthanized due to suspected lymphoid neoplasia. At necropsy, most lymph nodes in both pups were markedly enlarged, some with distinct white nodules, the spleens were diffusely enlarged, and the intestinal mucosae were thickened. Histopathologic features consistent with disseminated large cell lymphoma were identified to varying degrees of severity in lymph nodes, bone marrow, liver, tonsils, spleen, liver, intestines, kidneys, lower urinary tract, and several other organs. Immunohistochemical staining of neoplastic cells was most consistent with B lymphocyte origin, with most cells staining positively for Pax 5 and CD20 with admixed small CD3-positive T lymphocytes and CD204-positive macrophages. PCR and sequencing identified a novel gammaherpesvirus, herein called miroungine gammaherpesvirus 3, from affected tissues. This virus is in a clade outside of named genera that utilize hosts in the suborder Caniformia. The present study is the first description of diffuse large B cell lymphoma with leukemic manifestation and concomitant detection of a novel gammaherpesvirus in free-living NESs. Further research regarding the prevalence of this new gammaherpesvirus and its associated pathogenesis in this species is indicated.

Clinical signs, treatment, and outcome for California sea lions (Zalophus californianus) with Sarcocystis-associated polyphasic rhabdomyositis.

OBJECTIVE: To describe clinical signs, treatment, and outcome for California sea lions (Zalophus californianus) with Sarcocystis-associated polyphasic rhabdomyositis. ANIMALS: 38 free-ranging juvenile to adult California sea lions examined at a rehabilitation center in California between September 2015 and December 2017. PROCEDURES: Medical records at The Marine Mammal Center were reviewed to identify sea lions in which sarcocystosis had been diagnosed. RESULTS: Clinical signs were highly variable and associated with polyphasic rhabdomyositis attributed to Sarcocystis neurona infection. Generalized severe muscle wasting, respiratory compromise, and regurgitation secondary to megaesophagus were the most profound clinical findings. Respiratory compromise and megaesophagus were associated with a poor prognosis. Eight of the 38 sea lions were treated and released to the wild, and 2 subsequently restranded and were euthanized. Two additional animals received no targeted treatment and were released. The remaining 28 animals were either euthanized or died during treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that unlike other marine mammals, which typically develop encephalitis, California sea lions with sarcocystosis often have polyphasic rhabdomyositis with highly variable clinical signs and that extensive diagnostic testing may be required to confirm the diagnosis. Treatment with an antiprotozoal drug in combination with corticosteroids may resolve clinical disease, but the prognosis is guarded.

Treatment of Canine Tooth Fractures in the Northern Elephant Seal ( Mirounga angustirostris): Three Cases.

The Marine Mammal Center (TMMC) in Sausalito, California, rescues, rehabilitates, and releases hundreds of stranded northern elephant seals ( Mirounga angustirostris) each year. Common causes for stranding include maternal separation, malnutrition, and trauma. Causes of trauma include shark bites, conspecific interactions, and anthropogenic factors. Several cases of fractured teeth, secondary to presumed trauma, are presented to the center each year. This case series describes surgical approach and treatment of 3 young northern elephant seals that were admitted to TMMC for rehabilitation with tooth fractures with pulp exposure of maxillary or mandibular canine teeth. All 3 seals were successfully released into their natural environment.

Polyphasic Rhabdomyositis in California Sea Lions (Zalophus Californianus): Pathology and Potential Causes.

A myositis syndrome has been recognized for more than a decade in California sea lions (CSLs; Zalophus californianus) but a detailed description of the lesions and potential causes of this condition is lacking. The tissues of 136 stranded CSLs with rhabdomyositis were examined. Rhabdomyositis was considered incidental in 67% (91/136) of the CSLs, and a factor contributing to the animal stranding (significant rhabdomyositis) in 33% (45/136). Of the 91 cases with incidental rhabdomyositis, lesions consisted of a few small foci of lymphohistiocytic inflammation. Of the 45 cases with significant rhabdomyositis, 28 (62%) also presented with major comorbidities such as leptospirosis (2 animals) and domoic acid toxicosis (6 animals), whereas 17 (38%) had severe polyphasic rhabdomyositis as the only major disease process associated with mortality. In these animals, most striated muscles had multiple white streaks and diffuse atrophy. Microscopically, there was myofiber necrosis surrounded by lymphocytes and histiocytes admixed with areas of myofiber regeneration, and/or moderate to severe rhabdomyocyte atrophy usually adjacent to intact Sarcocystis neurona cysts. At the interface of affected and normal muscle, occasional T lymphocytes infiltrated the sarcoplasm of intact myocytes, and occasional myofibers expressed MHCII proteins in the sarcoplasm. S. neurona antibody titers and cyst burden were higher in animals with significant polymyositis antibody titers of (26125 ± 2164, 4.5 ± 1.2 cysts per section) and active myonecrosis than animals with incidental rhabdomyositis antibody titers of (7612 ± 1042, 1.7 ± 0.82 cysts per section). The presented findings suggest that S. neurona infection and immune-mediated mechanisms could be associated with significant polyphasic rhabdomyositis in CSLs.

ISOLATION AND CHARACTERIZATION OF A NOVEL MARINE BRUCELLA FROM A SOUTHERN SEA OTTER (ENHYDRA LUTRIS NEREIS), CALIFORNIA, USA.

We characterize Brucella infection in a wild southern sea otter ( Enhydra lutris nereis) with osteolytic lesions similar to those reported in other marine mammals and humans. This otter stranded twice along the central California coast, US over a 1-yr period and was handled extensively at two wildlife rehabilitation facilities, undergoing multiple surgeries and months of postsurgical care. Ultimately the otter was euthanized due to severe, progressive neurologic disease. Necropsy and postmortem radiographs revealed chronic, severe osteoarthritis spanning the proximal interphalangeal joint of the left hind fifth digit. Numerous coccobacilli within the joint were strongly positive on Brucella immunohistochemical labelling, and Brucella sp. was isolated in pure culture from this lesion. Sparse Brucella-immunopositive bacteria were also observed in the cytoplasm of a pulmonary vascular monocyte, and multifocal granulomas were observed in the spinal cord and liver on histopathology. Findings from biochemical characterization, 16S ribosomal DNA, and bp26 gene sequencing of the bacterial isolate were identical to those from marine-origin brucellae isolated from cetaceans and phocids. Although omp2a gene sequencing revealed 100% homology with marine Brucella spp. infecting pinnipeds, whales, and humans, omp2b gene sequences were identical only to pinniped-origin isolates. Multilocus sequence typing classified the sea otter isolate as ST26, a sequence type previously associated only with cetaceans. Our data suggest that the sea otter Brucella strain represents a novel marine lineage that is distinct from both Brucella pinnipedialis and Brucella ceti. Prior reports document the zoonotic potential of the marine brucellae. Isolation of Brucella sp. from a stranded sea otter highlights the importance of wearing personal protective equipment when handling sea otters and other marine mammals as part of wildlife conservation and rehabilitation efforts.

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.

Adrenal Gland and Lung Lesions in Gulf of Mexico Common Bottlenose Dolphins (Tursiops truncatus) Found Dead following the Deepwater Horizon Oil Spill.

A northern Gulf of Mexico (GoM) cetacean unusual mortality event (UME) involving primarily bottlenose dolphins (Tursiops truncatus) in Louisiana, Mississippi, and Alabama began in February 2010 and continued into 2014. Overlapping in time and space with this UME was the Deepwater Horizon (DWH) oil spill, which was proposed as a contributing cause of adrenal disease, lung disease, and poor health in live dolphins examined during 2011 in Barataria Bay, Louisiana. To assess potential contributing factors and causes of deaths for stranded UME dolphins from June 2010 through December 2012, lung and adrenal gland tissues were histologically evaluated from 46 fresh dead non-perinatal carcasses that stranded in Louisiana (including 22 from Barataria Bay), Mississippi, and Alabama. UME dolphins were tested for evidence of biotoxicosis, morbillivirus infection, and brucellosis. Results were compared to up to 106 fresh dead stranded dolphins from outside the UME area or prior to the DWH spill. UME dolphins were more likely to have primary bacterial pneumonia (22% compared to 2% in non-UME dolphins, P = .003) and thin adrenal cortices (33% compared to 7% in non-UME dolphins, P = .003). In 70% of UME dolphins with primary bacterial pneumonia, the condition either caused or contributed significantly to death. Brucellosis and morbillivirus infections were detected in 7% and 11% of UME dolphins, respectively, and biotoxin levels were low or below the detection limit, indicating that these were not primary causes of the current UME. The rare, life-threatening, and chronic adrenal gland and lung diseases identified in stranded UME dolphins are consistent with exposure to petroleum compounds as seen in other mammals. Exposure of dolphins to elevated petroleum compounds present in coastal GoM waters during and after the DWH oil spill is proposed as a cause of adrenal and lung disease and as a contributor to increased dolphin deaths.

Cloacolithiasis and intestinal lymphosarcoma in an African black-footed penguin (Spheniscus demersus).

A 13-yr-old male African black-footed penguin (Spheniscus demersus) presented thrice over 7 mo with gastrointestinal obstruction secondary to cloacolithiasis. Clinical signs consistently resolved with cloacolith removal and supportive care. However, 10 mo after initial presentation, it presented with similar signs, plus significant weight loss. No cloacolith was found, and it subsequently died. Significant gross findings included bilateral cecal masses, colonic perforation, and marked secondary coelomitis, multifocal tan to pale hepatic nodules, and pale kidneys with miliary white foci. Histopathologic diagnoses were intestinal lymphosarcoma with hepatic and renal metastases, secondary intestinal rupture, and subacute severe bacterial coelomitis. To the authors' knowledge, this is the first full report of either cloacolithiasis or lymphosarcoma in a penguin.

Presumed reactive polyarthritis and granulomatous vasculitis in a Mississippi sandhill crane (Grus canadensis pulla).

A 1.5-year-old female Mississippi sandhill crane (Grus canadensis pulla) was presented and managed for a polyarthritis of the intertarsal and tarsophalangeal articulations. Results of aerobic bacterial cultures, Mycoplasma species culture, and polymerase chain reaction testing of articular fluid did not identify any causative organisms. Results of radiographs and cytologic examination of articular fluid were consistent with an inflammatory, nonerosive polyarthritis. The arthritis did not improve with systemic anti-inflammatory and antibiotic treatment and with joint lavage. A large necrotic granulomatous mass was detected on the right shoulder area from which Staphylococcus aureus and Enterococcus species were isolated as opportunistic pathogens. Two days after surgical resection of the mass, the distal polyarthritis resolved. Histopathologic examination of the mass was consistent with granulomatous vasculitis with abscess formation of unknown origin. In this crane, the unresponsiveness to standard therapy, the presence of an infected and inflammatory mass, and the resolution of the polyarthritis after the resection of the mass strongly supported a diagnosis of reactive immune-mediated nonerosive polyarthritis. Analysis of this case suggests that immune-mediated idiopathic arthritis should be a differential diagnosis of distal polyarthritis in cranes and that an inciting source remote from the joints should be investigated in case of lack of response to standard therapy.

Endoscopic evaluation and biopsy collection of the gastrointestinal tract in the green moray eel (Gymnothorax funebris): application in a case of chronic regurgitation with gastric mucus gland hyperplasia.

A green moray eel (Gymnothorax funebris) was evaluated for chronic regurgitation. By using flexible endoscopy, the gastrointestinal tract was evaluated and revealed multifocal proliferative gastric masses and an intestinal ulcer. Biopsy specimens revealed gastric mucus gland hyperplasia, intestinal nematodiasis, and mild enteritis. Esophagoscopy and gastroscopy were performed by using a larger endoscope (length, 200 cm). A smaller endoscope (length, 100 cm) facilitated entering the intestinal tract in normograde or retrograde directions. A control eel was also evaluated, and no gross or histologic abnormalities were detected. The case eel was treated with metoclopramide and fenbendazole, responded well to therapy, and regurgitation decreased. A year later, the animal died of unrelated causes. Necropsy revealed coelomic gastric adhesions. The gastric proliferative lesions were associated with degeneration and necrosis of gastric pit mucosa without significant inflammation; etiology was unknown. Gastrointestinal endoscopy proved a useful diagnostic tool for evaluation and biopsy collection in this eel species.

Hiatal hernia in a harbor seal (Phoca vitulina) pup.

A 2-wk-old stranded harbor seal (Phoca vitulina) rescued by Mystic Aquarium showed signs of the presence of a hiatal hernia during rehabilitation. Contrast radiographs of esophagus and stomach revealed an intrathoracic radiodensity that contains filling defects typical of stomach, consistent with gastric rugal folds. Mural thickening was observed at the level of the cardia consistent with a diagnosis of a hiatal hernia. Although clinical improvement was noted with medical therapy and tube feeding, surgical correction of the hiatal hernia was considered necessary for full resolution. However, owing to the animal's low body weight, the corrective hernia surgery was postponed until the body condition improved. The seal needed to be surgically treated for a corneal ulcer, and while anesthetized with isoflurane, the seal became dyspneic and developed cardiac arrhythmias; ultimately cardiac arrest ensued. Resuscitation was unsuccessfully attempted and the seal was euthanized. Necropsy confirmed the radiographic diagnosis and further characterized a paraesophageal hiatal hernia.

Systemic mycosis in a California sea lion (Zalophus californianus) with detection of cystofilobasidiales DNA.

A 6-yr-old, intact male California sea lion (Zalophus californianus) with a systemic mycosis died after 5 wk of antifungal drug therapy. Antemortem clinical findings included hind flipper swelling, ring-lesions on skin of the flippers, and dermal nodules that increased in size and number spreading from the hind flippers and ventral abdomen to the foreflippers and muzzle. Lesions were accompanied by severe lymphadenopathy and development of systemic clinical signs despite therapy using itraconazole and later voriconazole. Histopathologic evaluation of biopsies revealed granulomatous dermatitis due to infection by fungus-producing yeast cells in tissue. Isolation attempts, using biopsied skin and tissue samples collected at necropsy, failed to yield growth of a fungus producing yeast cells like those in histologic section. Consensus polymerase chain reaction (PCR) tests of biopsied skin for fungal DNA produced an amplicon having significant sequence identity with a Cystofilobasidiales, a fungus belonging to a subclade that includes several Cryptococcus spp. Histopathologic evaluation of necropsy tissues revealed a systemic mycosis with yeast cells disseminated throughout subcutis, lymph nodes, and viscera. Hepatic necrosis was identified associated with acute liver failure, possibly from the voriconazole administration. This is the first report documenting the clinical presentation, treatment, and pathologic findings of infection associated with Cystofilobasidiales in a marine mammal and serves to expand the understanding of mycoses in pinnipeds.

Discospondylitis caused by Staphylococcus aureus in an African black-footed penguin (Spheniscus demersus).

A 22-year-old female African black-footed penguin (Spheniscus demersus), housed indoors with other African and rockhopper penguins, was presented acutely with lethargy, ataxia, and hind limb weakness after a molt. The penguin would assume a hunched position and, when resting, sat on its hocks or lay on its keel. Physical and neurologic examination revealed hind limb paraparesis, proprioceptive deficits, and tiptoe walking. Results of a complete blood cell count and biochemical analysis revealed mild heterophilic leukocytosis, anemia, mild hypoalbuminemia, hypokalemia, and hyperuricemia. Results of whole-body radiographs and coelioscopy were unremarkable. Two computed tomographies of the spine at a 3-month interval revealed a lesion at the mobile thoracic vertebra proximal to the synsacrum with associated spinal cord compression. The penguin was treated with itraconazole, doxycycline, and meloxicam, and it initially improved with return to near normal gait and behavior. However, 5 months after the onset of clinical signs, the penguin was euthanatized after a relapse with worsening of the neurologic signs. Postmortem and histopathologic examination revealed focal granulomatous discospondylitis at the penultimate mobile thoracic vertebra, with intralesional bacteria from which Staphylococcus aureus was cultured.