Extra-adrenal retroperitoneal paraganglioma in a dog.

An extra-adrenal retroperitoneal paraganglioma was observed in a 10.5-year-old male Boxer dog. Additionally, the dog had an aortic base tumor, multiple thyroid adenomas, multiple testicular interstitial cell tumors, bilateral nodular adrenal cortical hyperplasia, and parathyroid gland hyperplasia. The hypothesis that the retroperitoneal mass represents a primary extra-adrenal paraganglioma rather than metastatic mass from the aortic body tumor is considered. Either primary or metastatic extra-adrenal retroperitoneal paragangliomas are rarely reported in dogs.

Histologic findings in free-ranging Sarasota Bay bottlenose dolphin (Tursiops truncatus) skin: mercury, selenium, and seasonal factors.

Full-thickness epidermal biopsy samples were collected from free-ranging common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida, USA. Season (summer or winter) of collection, mercury (Hg) concentration, and selenium (Se) concentration were compared to histologic parameters. Epidermal Hg concentration was positively related to age (P<0.001) and negatively related to height of the stratum spinosum (P<0.05). The mitotic index and heights of the stratum externum and intermedium were lower in summer than in winter (P<0.01). Transmission electron microscopic examination revealed variation in the diameters (60-138 nm) and arrangements of collagen fibers, regardless of age or concentrations of Hg and Se. The significance of the variation in height of the stratum spinosum and the perivascular collagen degeneration to dolphin health need further investigation.

Feeding Behavior-Related Toxicity due to Nandina domestica in Cedar Waxwings (Bombycilla cedrorum).

Dozens of Cedar Waxwings were found dead in Thomas County, Georgia, USA, in April 2009. Five of these were examined grossly and microscopically. Grossly, all the examined birds had pulmonary, mediastinal, and tracheal hemorrhages. Microscopically, several tissues and organs were diffusely congested and hemorrhagic. Congestion and hemorrhage were marked in the lungs. Intact and partly digested berries of Nandina domestica Thunb. were the only ingesta found in the gastrointestinal tract of these birds. Due to their voracious feeding behavior, the birds had eaten toxic doses of N. domestica berries. N. domestica contains cyanide and is one of the few berries readily available at this time of the year in the region. The gross and microscopic findings are consistent with lesions associated with cyanide toxicity. This paper for the first time documents toxicity associated with N. domestica in Cedar Waxwings.

Amphibian ocular malformation associated with frog virus 3.

During an on-going amphibian ecology study, a free-ranging American bullfrog (Rana catesbeiana) metamorph was captured in a pitfall trap adjacent to a constructed farm pond at the Plateau Research and Education Center (PREC) on the Cumberland Plateau near Crossville, Tennessee, USA. Grossly, the right eye was approximately 50% the size of the left. Stereo and light microscopic examination revealed two granulomas within the orbit. Electron microscopic examination revealed virus particles scattered throughout one structure but mostly aggregated toward the center. Subsequent PCR and sequencing (GenBank accession Number EF175670) confirmed frog virus 3 (FV3). This represents the first report of a malformation in an anuran associated with FV3.

Superoxide dismutase expression and oxidative damage in a case of myopathy in brown pelicans (Pelecanus occidentalis).

Four brown pelicans (Pelecanus occidentalis) housed at a rehabilitation facility were found dead after a 3-day history of muscle weakness and after being fed for about 2 weeks from a recent shipment of fish. The birds had pale streaking of the skeletal and heart muscles. Microscopically, the skeletal muscle, and to a lesser extent the cardiac muscle, had severe myocyte degeneration and necrosis characterized by microvacuolation with loss of cross-striations, condensation of cytoplasm, fragmentation, mineralization, and inflammatory cell infiltrates consisting of multinucleated cells, macrophages, and few heterophils. The findings were consistent with myopathy, and a nutritional myopathy caused by eating rancid fish was suspected. Immunohistochemical staining revealed abundant immunoreactive copper zinc superoxide dismutase and manganese superoxide dismutase either as diffuse homogeneous precipitates or granular aggregates in the cytoplasm of affected cells. Immunoreactivity was directly related to degree of cellular damage as estimated by light microscopic examination. We suggest that the lack of protection, despite upregulation of superoxide dismutase, is most likely attributable to supersaturation of oxidants beyond the capacity of superoxide dismutases to scavenge.

Occurrence of Piscirickettsiosis-like syndrome in tilapia in the continental United States.

From 2001 to 2003, tilapia (Oreochromis sp.) farms in Florida, California, and South Carolina experienced epizootics of a systemic disease causing mortality. The fish exhibited lethargy, occasional exophthalmia, and skin petechia. The gills were often necrotic, with a patchy white and red appearance. Grossly, the spleen and kidneys were granular with whitish irregular nodules throughout. Granulomatous infiltrates were observed in kidney, spleen, testes, and ovary tissues, but not in the liver. The granulomas contained pleomorphic coccoid bacteria, measuring 0.57 +/- 0.1 x 0.8 +/- 0.2 microm, that were Giemsa-positive, acid-fast-negative, and Gram-negative. The bacteria had a double cell wall, variable electron-dense and -lucent areas, and were present in the cytoplasm and within phagolysosomes. The syndrome was associated with cold stress and poor water conditions. These findings are consistent with an infectious process caused by a Piscirickettsia-like bacterium described previously in tilapia in Taiwan and Hawaii. This report involves the first identified cases of a piscirickettsiosis-like syndrome affecting tilapia in the continental United States.

Prunus spp. intoxication in ruminants: a case in a goat and diagnosis by identification of leaf fragments in rumen contents.

Prunus serotina Ehrh. (black cherry) intoxication was diagnosed on postmortem examination of a goat. The clinical signs were weakness, depression, seizure-like activity, and lateral recumbency. Natural cases of black cherry intoxication have not been reported in goats in the United States. In the absence of a history of access to black cherry or the ability to detect cyanide or cyanogenic glycosides in blood or tissues, black cherry intoxication may be diagnosed in ruminants by the identification of black cherry leaves in rumen contents. Three distinctive features facilitate identification of black cherry leaves or leaf fragments: 1) a pair of small glands that protrude from the sides of the petiole just below the base of the blade, 2) incurved, gland-tipped (callous) teeth along the margins of the leaf, and 3) a band of hairs to each side of the lower half of the midvein on the surface of the leaf. Shape of the marginal teeth, presence or absence of glands at the tips of these teeth, the morphology of these glands, and presence or absence of petiolar glands and their morphology may allow identification and differentiation of small fragments of leaves from the 6 most important cyanogenic Prunus spp. in eastern North America: black cherry, Carolina laurel cherry, peach, English laurel cherry, choke cherry, and fire cherry.

Electron microscopic study of canine Babesia gibsoni infection.

Canine babesiosis is a tick-borne parasitic disease caused by the intraerythrocytic parasites, Babesia canis and Babesia gibsoni. A lethargic, weak, American Staffordshire Terrier (pit bull) dog, which had regenerative, normocytic, normochromic anemia, was shown by polymerase chain reaction analysis to be infected with B. gibsoni. Transmission electron microscopy of ethylenediamine tetraacetic acid-treated blood disclosed many well-preserved, intraerythrocytic babesia trophozoites. Four morphologic forms of babesia trophozoites are described (small spheres, small rods, irregular forms lacking pseudoinclusions, and large spheres having pseudoinclusions) and are compared with intraerythrocytic forms of B. canis and B. gibsoni described in other light and electron microscopic studies of in vivo and in vitro Babesia infections. This is the first detailed transmission electron microscopic study of canine B. gibsoni-infected red blood cells in North America.

Preliminary characterization of chemically generated Mycobacterium avium subsp. paratuberculosis cell wall deficient forms (spheroplasts).

Cell wall deficient forms (CWD, spheroplasts) genetically indistinguishable from M. avium subsp. paratuberculosis (MAP) have been isolated from patients with Crohn's disease and sarcoidosis. These MAP CWD may be important in the pathogenesis of these diseases and in Johne's Disease in other animal species. CWD forms are extremely difficult to isolate and generally revert to cell wall competent forms (CWC) when cultured in vitro. Cultured MAP strain 19698 were chemically treated to generate sufficient CWD to compare to CWC organisms by electron microscopy, chemotype profile (matrix solid-phase dispersion and thin layer chromatography), silver-stained SDS-PAGE gels with and without periodic acid treatment and Western blots with antigen recognition by sera from confirmed Johne's positive and Johne's negative cattle. On electron microscopy, CWD organisms were larger and rounder than cell wall competent forms and had lost the majority of their cell walls, being bounded only by a plasma membrane. Chemotype profiles of CWD lacked bands generally associated with cell wall glycolipids. Silver-stained SDS-PAGE gels of CWD demonstrated loss of bands that migrate in the same region as lipoarabinomannan (LAM) and some bands likely representing proteins and weakening of bands that migrate similarly to phosphatidylinositol mannosides (PIM). Western blots of CWD demonstrated bands with loss or attenuation of signal that migrate similarly to LAM and other constituents. In summary, CWD and CWC forms of MAP 19698 had marked differences in morphology, chemotype profile, cell wall constituents, and antigens recognized by Johne's disease positive and negative bovine sera.

Septicemic salmonellosis in two cats fed a raw-meat diet.

Salmonella gastroenteritis and septicemia were diagnosed in two cats presented for necropsy. Both cats resided in the same household and were fed a home-prepared, raw meat-based diet. Salmonella was isolated from multiple organs in both cats and from samples of raw beef incorporated into the diet fed to one of the cats. Subtyping of the bacterial isolates yielded Salmonella newport from one cat and from the diet it had been fed. This report provides evidence that the practice of feeding raw meat-based diets to domestic cats may result in clinical salmonellosis.

Multiple animal intoxications associated with Carolina jessamine (Gelsemium sempervirens) ingestions.

Neurological signs characterized by marked progressive weakness and convulsions culminating in death were observed in 3 goats over a 24-h period. Affected animals were in a group of 5 goats confined toa fenced paddock: a domestic goose within the paddock was also found dead. Present in the same paddock, but unaffected, were 2 other goats and an adult cow. Five days prior to the animals' deaths, the owner had trimmed the surrounding brush and had thrown the cuttings into the enclosure. Post mortem examination of 2 of the dead goats and the goose revealed reduced muscle mass and fat stores, serous atrophy of adipose tissue, and reduced gastrointestinal contents, which included numerous leaves identified as Carolina jessamine (Gelsemium sempervirens). Histologic lesions included mild diffuse neuronal degeneration and cerebellar Purkinje cell loss in all animals with mild multifocal vacuolation of brainstem and cerebral white matter in 1 goat, and myofiber atrophy with perimyseal fibrosis in the goose. Preexisting malnutrition and lack of adequate alternative forages likely resulted in ingestion of Carolina jessamine and subsequent toxicosis. To our knowledge, this is the first reported case of Carolina jessamine toxicosis in goats and geese.

Thymic hematoma in juvenile dogs associated with anticoagulant rodenticide toxicosis.

Ten cases of thymic hematoma in young dogs (9-24 weeks of age) were reviewed. Anticoagulant rodenticide toxicosis was confirmed in 5 cases. Histologically, hemorrhage caused variable expansion of thymic lobules and interlobular septa. The medulla appeared to be the primary site of hemorrhage. In areas of severe hemorrhage, normal lobular architecture was lost and lymphocytes were admixed in the hemorrhagic exudate. Vasculitis, necrosis of capillaries, and degeneration of the capsule were observed in infarcted areas. In 2 cases, angiofibroplasia indicated a longer interval between onset of thymic hemorrhage and death. The lesions are similar to those in 5 cases of idiopathic thymic hemorrhage. Appropriate samples were not available for anticoagulant rodenticide analysis in 3 of these 5 idiopathic cases. Lesions in confirmed cases of anticoagulant rodenticide toxicosis also are compatible with published descriptions of idiopathic and spontaneous thymic hemorrhage, but are inconsistent with normal thymic involution. Analysis for anticoagulant rodenticides is indicated in cases of thymic hematoma when an obvious cause is not detected at necropsy.

Thyroid c-cell carcinoma in an African pygmy hedgehog (Atelerix albiventris).

A 3-yr-old African pygmy hedgehog (Atelerix albiventris) was submitted with dysphagia, weight loss, and tetraparesis. A palpable mass was found on the ventral neck. Histologic examination revealed replacement of the thyroid gland by a highly cellular, expansile, and infiltrative mass composed of lobules of polygonal cells separated by fine fibrovascular septa. Examination of ultrathin sections revealed tumor cells with few to many dense-core neuroendocrine granules, approximately 100-200 nm in diameter, and stromal amyloid. Immunohistochemical stains were positive for neuron-specific enolase. Only rare cells had positive immunohistochemical staining for calcitonin. Findings are consistent with a neuroendocrine tumor of C-cell origin. This is the first report of a C-cell carcinoma in a hedgehog.