Cutaneous mast cell tumor in a captive Bush dog (Speothos venaticus): pathological and immunophenotypical aspects - case report

ABSTRACT A senile male captive bush dog (Speothos venaticus) presented a small perianal cutaneous nodule. Histologically, there was an ulcerated round cell tumor composed of well differentiated mast cells with abundant intracytoplasmic purple Giemsa-positive granules, with a diffuse eosinophilic infiltrate. Immunohistochemistry revealed that 30% of the neoplastic cells were positive for Kit in the cytoplasm and cell membrane, and all neoplastic cells were negative for MAC and CD3. Less than 10% of the neoplastic cells were positive for Ki67. At necropsy other primary tumors were identified in this animal, including an intestinal adenoma, an adrenal cortex adenoma and a testicular interstitial cell tumor.

Primeiro registro do cachorro-vinagre Speothos venaticus (Carnivora, Canidae) para a Mata Atlântica do estado do Rio Grande do Sul, sul do Brasil

O cachorro-vinagre (Speothos venaticus) é um dos seis representantes da família Canidae no Brasil, estando presente em quase todos os biomas do país. Sua distribuição vai da Costa Rica e Panamá até a província de Misiones, na Argentina, e o estado de Santa Catarina, no Brasil. Além de naturalmente raro, é considerado de difícil detecção pelo seu comportamento elusivo e pouco conhecido. O presente estudo visa descrever o primeiro registro do cachorro-vinagre para o estado do Rio Grande do Sul, expandindo assim sua área de ocorrência e distribuição confirmada. Tendo sido observados oportunisticamente no dia 05 de julho de 2020, dois indivíduos foram fotografados dentro do Parque Estadual do Turvo, na região noroeste do estado. Tal encontro ressalta a relevância das Unidades de Conservação na manutenção das populações da fauna ameaçada de extinção. Sugere-se a classificação como “criticamente ameaçada” para a espécie no estado do Rio Grande do Sul e recomenda-se a sua inclusão na lista de espécies ameaçadas da fauna no estado.

Checklist of large and medium-bodied mammals from four areas of Tocantins state, Central Brazil

The state of Tocantins is located in Central Brazil. The northern extreme of this state corresponds to the southeastern portion of the Amazon biome, while it is covered primarily by Cerrado savanna, as well as the transition area between these two biomes. We provide a checklist of large- and medium-bodied mammals from four localities in Tocantins, update the list of species for the state, and compile the available information on their geographic distribution. We surveyed mammals at four sites during different periods (between 2010 and 2018), using camera traps and opportunistic observations. In spite of the differences in the sampling effort among the sites, we recorded 42 mammal species belonging to eight orders and 20 families. Our list includes rare and threatened species, such as the jaguar (Panthera onca), the giant anteater (Myrmecophaga tridactyla), and the lowland tapir (Tapirus terrestris). One species (Galictis cuja) was recorded in the state for the first time and the known range distribution of two others (Speothos venaticus and Alouatta caraya) was updated.

First photographic records of bush dogs (Speothos venaticus) from camera-traps in Guyana

The bush dog (Speothos venaticus) is rare, elusive, and difficult to study in the wild. Guyana contains a wealth of intact tropical forest (∼18.4 million ha) and savanna (1.6 million ha) habitats, but management of this species is hindered by a lack of data. We present two photographic records (consisting of nine individuals) of bush dogs from camera-traps set in the Kanuku Mountains Protected Area (KMPA) – the first of this species in Guyana. These records highlight the importance of Guiana Shield forests and Guyana’s expanding protected areas system to the conservation of these wide-ranging carnivores. Additionally, we recommend that detailed measurement and reporting of site variables become standard, as it will improve the efficacy of camera-trap studies of bush dogs and allow for broad-scale modelling of space use not otherwise possible due to the low detection rates at the scale of each individual study.

Atropelamento de fauna silvestre em uma Reserva da Biosfera no Brasil: ameaças à conservação do Pantanal Norte do Brasil

Animais silvestres são atropelados por veículos automotores, causando a morte ao longo de rodovias. Estima-se que 476 milhões de animais silvestres são mortos a cada ano no Brasil. O Pantanal Norte, no bioma brasileiro de Mato Grosso, é uma região que vem ao longo da sua história de uso e ocupação, sofrendo grandes pressões antrópicas, principalmente atividades de garimpo, mineração, pesca desportiva e profissional predatória, introdução de espécies, agricultura, pecuária e urbanização. A rodovia MT – 040 (Estrada-Parque Santo Antônio – Barão de Melgaço com 112 Km até Barão de Melgaço (Pantanal Norte). O objetivo deste estudo foi registrar atropelamentos de animais silvestres por veículos automotores ao longo da Estrada Parque (Pantanal Norte de Mato Grosso). Os cadáveres dos animais atropelados foram fotografados e identificados por zoólogos especialistas, através de fotos, georreferenciadas. Obtive-se como resultados a ocorrência de 86 (oitenta e nove) animais, pertencentes a 9 (seis) ordens diferentes. Identificou-se as seguintes espécies: 34 Capivaras (Hydrochoerus hydrochaeris), 10 Quati (Nasua nasua), 6 Tamandua-bandeira (Myrmecophaga tridactyla), 1 Gavião-belo (Busarellus nigricollis), 12 jacaré-do-pantanal (Caiman yacare), 7 Tamanduá-mirim (Tamandua tetradactyla), 17 cahorro-do-mato (Speothos venaticus), 1 sucuri (Eunetctus murinus) e 1 jibóia (Boa constrictor). Constatou-se a predominância da mortandade de mamíferos e das ordens Rodentia, Pilosa e carnívora, durante o período de cheia. Devido a relevância deste estudo, faz-se necessário o monitoramento constante de animais silvestres na região, conhecer sua biologia e principalmente criar políticas públicas que visem a fiscalização, conservação e minimizar os impactos causados nesses ecossistema naturais.

Pediculectomy and fenestration for spinal cord decompression of the lumbar spine of a bush dog (Speothos venaticus) - case report

ABSTRACT A captive adult male bush dog (Speothos venaticus) was referred to our Veterinary Medical Teaching Hospital from a local zoo due to a two-week history of progressive hind limb gait impairment and ataxia, non-responsive to clinical management. Computed tomography revealed decreased disc space at L3 - L4 level, with probable disc extrusion narrowing the right side of the spinal canal, compressing the spinal cord. We opted to surgically remove the disc material using both fenestration and right lateral pediculectomy (mini-hemilaminectomy) techniques. Twelve days after surgery there was mild residual proprioceptive ataxia. Gait was fully regained with remission of the neurological deficits around the 30th postoperative day. This is - to the best of our knowledge - the first successful report of a lumbar intervertebral disc extrusion in a bush dog (Speothos venaticus) surgically treated by pediculectomy and disc fenestration.

Extranodal lymphoma in a bush dog (Speothos venaticus) - case report

ABSTRACT A captive 7-year-old male bush dog (Speothos venaticus) was diagnosed with lymphoma affecting the kidneys, adrenal glands, liver, and spleen. The animal developed renal failure and was euthanized due to poor prognosis. Grossly, both kidneys were enlarged with multiple nodules. Histologically, the neoplasm was an infiltrative and poorly demarcated round cell tumor. Two morphologically distinct cell populations were observed, smaller cells with a lymphocytic morphology, and another population of larger and pleomorphic cells. Most of the smaller cell population, approximately 40% of the population within the neoplasm, were CD3 positive. Neoplastic cells were CD45, CD11d, and granzime B positive, and negative for CD20, CD79a, PAX5, CD163, and myeloperoxidase. This is the first reported case of lymphoma in a bush dog. This report demonstrated the suitability of several cell surface markers for differential diagnosis of round cell tumors in this species.