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.

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.

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.

Assessment of Hazardous Metal Concentrations in Organs of Selected Game Animals in the Natural Environment

The study was conducted to determine the levels of hazardous metals in game animals. A total of eighteen (18) animals which comprised six species of three (3) each from the same location were trapped or hunted and sacrificed. Organs analyzed for hazardous metal levels were skin, liver, kidney and heart using Atomic Absorption Spectrometry and content expressed in mgkg-1. The statistical analysis was done with Genstat (2007). Results obtained showed that all the hazardous metals under study were present in the organs at variable concentrations. Lead: skin (0.18 – 0.46) mgkg-1, liver (0.03 – 0.4) mgkg-1, heart (0.25 – 0.58) mgkg-1 and kidney (0.38 1.12) mgkg-1; Cadmium: skin (0.08 – 0.58) mgkg-1 and kidney (0.09 – 0.7) mgkg-1; Zinc : skin ( 0.46 – 0.66) mgkg-1, liver (90.04 – 0.82) mgkg-1, heart (0.42 – 1.21) mgkg-1 and kidney (0.43 – 1.58) mgkg-1; Copper: skin (6.13 – 12.57) mgkg-1, liver (5.1 – 9.56) mgkg-1, heart (6.89 - 15.15) mgkg-1 and kidney (7.63 – 24.87) mgkg-1; Iron : skin (9.53 – 26.35) mgkg-1, liver (8.07 -28.08) mgkg-1, heart (13.83 - 46.40) mgkg-1 and kidney (12.43 – 47.61) mgkg-1. Iron was highly (p <0.05) deposited in all species of animals in the heart 19.88 mgkg-1, 46.40 mgkg-1, 40.83 mgkg-1, 13.83 mgkg-1 and 41.38 mgkg-1 respectively for civet (Civettictis civeta), antelope (Antilocapra americana), grasscutter (Thryonomys swiderianus), hedgehog (Atelerix albiventris) and bush dog (Speothos venaticus) except the bush rat (Rattus fuscipes) that had its highest deposition (46.71 mgkg-1) in the kidney. Copper was also highly deposited in animals after iron with higher concentrations in heart and kidney. The highest concentration was recorded for bush rat (Rattus fuscipes) (15.15 mgkg-1) in heart and 24.87 mgkg-1 in kidney. Due to bioaccumulation of hazardous metals, care should be taken in patronizing bushmeat obtained from the studied ecosystem since failure could be perilous to the health of consumers as their concentrations are beyond the safe limits for the respective metals. It is further recommended that environmental safety principles for safe disposal of hazardous metals are appropriately carried out.

Comparative Study of the Bush Dog (Speothos venaticus) Karyotype and Analysis of Satellite DNA Sequences and Their Chromosome Distribution in Six Species of Canidae

The bush dog (Speothos venaticus, 2n = 74) is a near threatened species taxonomically classified among South American canids. We revised the bush dog karyotype and performed a comparative sequence analysis of satellite and satellite-like DNAs in 6 canids: the bush dog, domestic dog (Canis familiaris, 2n = 78), grey wolf (C. lupus, 2n = 78), Chinese raccoon dog (Nyctereutes procyonoides procyonoides, 2n = 54+B), red fox (Vulpes vulpes, 2n = 34+B), and arctic fox (V. lagopus, 2n = 48-50) to specify the species position among Canidae. Using FISH with painting and BAC probes, we found that the distribution of canid evolutionarily conserved chromosome segments in the bush dog karyotype is similar to that of the domestic dog and grey wolf. The bush dog karyotype differs by 2 acrocentric chromosome pairs formed by tandem fusions of the canine (29;34) and (26;35) orthologues. An interstitial signal of the telomeric probe was observed in the (26;35) fusion site in the bush dog indicating a recent evolutionary origin of this rearrangement. Sequences and hybridisation patterns of satellite DNAs were compared, and a phylogenetic tree of the 6 canid species was constructed which confirmed the bush dog position close to the wolf-like canids, and apart from the raccoon dog and foxes.

Bush Dogs in Central America: Recent Range Expansion, Cryptic Distribution, or Both?

Bush dogs ( Speothos venaticus) are a small, wide-ranging neotropical pack-hunting canid whose ecology is relatively poorly known. Here, we document new, repeated observations of bush dog groups in east-central (Barbilla National Park) and south-eastern (La Amistad International Park) Costa Rica that suggest either that their recent or historic range has been underestimated, or that their potential range in Central America may have recently expanded and could now include not only borderlands with Panama but perhaps a substantial portion of the Talamanca Mountains up to 120 km to the north-northwest and at elevations up to 2,119 m. In light of their inherently low density, documenting the current and future distribution of bush dogs in Central America will be challenging.