Fatal disseminated blastomycosis in a free-ranging American black bear (Ursus americanus)

UTILITY OF URINE ANTIGEN TESTING FOR DIAGNOSIS OF BLASTOMYCOSIS IN NONDOMESTIC FELIDS

Blastomycosis caused by the fungus Blastomyces dermatitidis has been reported to cause disease in numerous species of nondomestic felids. Diagnosis of blastomycosis in domestic species often relies on the combination of clinical signs, radiographic findings, and commercial urinary antigen testing. In this report, the sensitivity, specificity, and positive and negative predictive values for urine blastomyces antigen testing for use in nondomestic felids were examined and compared with findings on postmortem examination. The study showed a sensitivity of 100%, specificity of 91.86%, positive predictive value of 50%, and negative predictive value of 100% for urine antigen testing. Furthermore, radiographic and hematologic findings were compared with those of animals diagnosed with blastomycosis. Radiographic evidence consistent with blastomycosis was found in those animals diagnosed via urine antigen testing, but no significant differences in plasma biochemistry parameters between diseased and nondiseased animals were found. This study provides evidence that a positive blastomycosis antigenuria test result should be combined with other diagnostic methods to confirm the presence of infection with B. dermatitidis, whereas a negative antigenuria test result is 100% effective in predicting the absence of disease.

Morphological and molecular phylogenetical identification of <i>Tricodectes pinguis</i> from Japanese black bears (<i>Ursus thibetanus japonicus</i>) in Aomori Prefecture, Japan

Trichodectes pinguis, referred to commonly as the bear-biting louse, has been reported in several bear species. However, graphical (blurred or coarse) and genetic information on the louse is limited. In this study, we identified T. pinguis collected from Japanese black bears in the Aomori Prefecture, Japan. We confirmed 12S rDNA sequences derived from the collected T. pinguis and performed molecular phylogenetic analysis based on 12S rDNA. The analysis revealed the parasitic louse to be T. pinguis. Interestingly, the body size of T. pinguis found in this study was smaller than the previous recorded body size of them in Japan and Turkey. To better understand the biting louse infesting bears, morphometric and genetic information from other bear hosts needs to be accumulated.

ASSAYS FOR DETECTION AND IDENTIFICATION OF THE CAUSATIVE AGENT OF MANGE IN FREE-RANGING BLACK BEARS ( URSUS AMERICANUS)

Three mite species ( Demodex ursi, Ursicoptes americanus, and Sarcoptes scabiei) have been associated with mange in black bears ( Ursus americanus). Since the early 1990s, the number and geographic distribution of mange cases in black bears in Pennsylvania, US has increased; however, the causative mites have yet to be completely defined. We evaluated several diagnostic approaches for detection and identification of mites in 72 black bears with severe lesions consistent with mange. Sarcoptes scabiei was morphologically identified in skin scrapes from 66 of the bears; no mites were identified in the remaining six. Histopathologic lesions consistent with sarcoptic mange were observed in 39 of 40 bear skin samples examined, and intralesional mites were observed in samples from 38 of these bears. Samples were collected from a subset of the 72 bears for PCR testing targeting both the internal transcribed spacer (ITS)-2 region and cytochrome c oxidase I ( cox1) gene including 69 skin scrapes ( ITS-2 only), 56 skin biopsies ( ITS-2 and cox1), and 36 fecal samples ( ITS-2 and cox1). Skin scrapes were a more sensitive sample for PCR detection than either skin biopsies or fecal samples, and the ITS-2 primers proved more sensitive than cox1. Using a commercial indirect enzyme-linked immunosorbent assay, antibodies to S. scabiei were detected in 45/49 (92%) black bears with confirmed mange and 0/62 (0%) cubs with no gross lesions suggestive of mange and which were born to seronegative sows. Sarcoptes scabiei was the predominant mite associated with mange in black bears in Pennsylvania. Diagnostically, cytologic examination of skin scrapes was the most effective approach for diagnosing active mite infestations in black bears. The evaluated serologic assay accurately detected antibodies to S. scabiei in most bears with confirmed S. scabiei infestations. Additional research is needed to determine the usefulness of this approach for larger scale surveys and for asymptomatic bears.

Blastomycosis in Mammals

Blastomycosis is a serious fungal disease of dogs, humans, and occasionally other mammals caused by geographically restricted, thermally dimorphic Blastomyces species. Blastomycosis is primarily a canine disease, with approximately ten dogs diagnosed for every human case. Dogs also develop disease more rapidly, thus becoming sentinels for possible human disease. Human and canine blastomycosis may differ according to epidemiology/epizoology, clinical features, performance and use of diagnostics, and management.

SYSTEMIC BLASTOMYCOSIS IN A CAPTIVE RED RUFFED LEMUR (VARECIA RUBRA)

A 5-yr-old, intact male red ruffed lemur ( Varecia rubra ) presented for evaluation as the result of a 1-wk history of lethargy and hyporexia. Physical examination findings included thin body condition, muffled heart sounds, harsh lung sounds, and liquid brown diarrhea. Complete blood count and serum biochemistry showed an inflammatory leukogram, mild hyponatremia, and mild hypochloremia. Orthogonal trunk radiographs revealed a severe alveolar pattern in the right cranial lung lobes with cardiac silhouette effacement. Thoracic ultrasound confirmed a large, hypoechoic mass in the right lung lobes. Fine-needle aspiration of the lung mass and cytology revealed fungal yeast organisms, consistent with Blastomyces dermatitidis. Blastomyces Quantitative EIA Test on urine was positive. Postmortem examination confirmed systemic blastomycosis involving the lung, tracheobronchial lymph nodes, spleen, kidney, liver, cerebrum, and eye. To the authors' knowledge, this is the first report of blastomycosis in a prosimian species.

Chewing lice Trichodectes pinguis pinguis in Scandinavian brown bears (Ursus arctos)

In April 2014 and 2015, we noted localized alopecia (neck, forelimbs, and chest) and hyperpigmentation on two adult brown bears (Ursus arctos) captured in central-south Sweden for ecological studies under the Scandinavian Brown Bear Research Project. In spring 2015, a brown bear was shot because of human-wildlife conflict in the same region. This bear also had extensive alopecia and hyperpigmentation. Ectoparasites were collected from the affected skin areas in all three individuals and preserved in ethanol for identification. Based on morphological characteristics, the lice were identified as Trichodectes spp. and Trichodectes pinguis pinguis. To our knowledge, these are the first reported cases of chewing lice in free-ranging brown bears in Scandinavia.

•

Trichodectes pinguis pinguis is the chewing lice of brown bears (Ursus arctos).

•

This is the first report of T. pinguis pinguis in brown bears in Scandinavia.

•

T. pinguis pinguis could cause alopecia, hyperpigmentation and lichenification of the bears' skin.

•

Infestations by T. pinguis pinguis could have an impact on the health of brown bears.

Probable Pulmonary Blastomycosis in a Wild Coyote (Canis latrans)

A female coyote (Canis latrans) was fatally injured by a vehicle on a road in San Luis Potosi, Mexico. Because of deteriorating clinical signs, the animal was euthanized. Postmortem examination of the lungs showed numerous small multifocal white nodules (0.5–1 cm diameter) disseminated throughout. Histopathologic examination revealed multifocal coalescing granulomas with abundant macrophages, numerous neutrophils, fibroblasts, plasma cells, and lymphocytes. Abundant intracellular and extracellular thick-walled, refractile, spherical yeasts (10–15 μm) were observed within the granulomas. The yeasts were intensely PAS-positive, with granular protoplasm. Broad-based single budding yeasts were occasionally present. Based on the microscopic findings of the pulmonary lesions and the morphological features of the organism, a diagnosis of chronic pyogranulomatous pneumonia caused byBlastomyces dermatitidiswas made. To our knowledge, the case described herein is the first report of pulmonary blastomycosis in a wild coyote.

Disseminated Blastomyces dermatitidis, genetic group 2, infection in an alpaca (Vicugna pacos)

A 7-year-old, female Huacaya alpaca presented with a 3-week history of left-sided head tilt and mild ataxia. Despite aggressive supportive therapy with empirical antibiotic, anti-inflammatory, thiamine, and anthelminthic therapy, neurologic signs progressed to a right-sided head tilt, positional nystagmus, and episodes of severe ataxia and obtundation. On necropsy, discrete expansile to poorly delineated infiltrative masses with tan, creamy to grumous exudate were observed in the right petrous temporal bone, right middle and inner ear, right cerebellum and medulla as well as in lung, kidney, liver, spleen, lymph nodes, and the gastrointestinal tract. Impression cytology and histology revealed a myriad of intralesional yeast, 10-25 μm in diameter, with double-contoured walls, granular protoplasm, and broad-based budding. Culture characteristics, including conidial morphology and temperature-dependent yeast phase transformation, were consistent with Blastomyces sp. Positive Blastomyces antigenuria was identified on a postmortem sample of urine. Microsatellite typing and sequencing of the internal transcribed spacer region 2 identified the infecting strain as a genetic group 2 isolate of Blastomyces dermatitidis. The present report of camelid blastomycosis adds intracranial blastomycosis to the differential list for camelid neurologic disease in endemic regions.