Thymoma-associated exfoliative dermatitis in a goat: case report and brief literature review.

A Rock Alpine doe (Capra aegagrus hircus) was presented to the Colorado State University Veterinary Teaching Hospital because of scaling and ulceration over the withers, coronary bands, and dewclaws. The doe was euthanized because of poor prognosis associated with a radiographically identified cranial mediastinal mass, increased respiratory effort, and discomfort. Autopsy revealed a cranial mediastinal mass, and scaling-to-ulcerative lesions affecting the dorsum, ventrum, pinna, neck, teats, coronary bands, and dewclaws. Histologically, the mediastinal mass was an epithelial neoplasm with admixed non-neoplastic T lymphocytes, consistent with a lymphoepithelial (mixed) thymoma. Sections of affected skin were characterized by hyperkeratotic cell-rich interface dermatitis with transepidermal and follicular apoptosis. Thymoma-associated exfoliative dermatitis has been recognized in cats and a rabbit, but has not been reported previously in a goat, to our knowledge. Given that thymomas are not uncommon in goats, thymoma-associated exfoliative dermatitis should be considered a clinical differential in goats with dermatologic disease.

Total mercury loadings in sediment from gold mining and conservation areas in Guyana.

The Low Carbon Development Strategy proposed in June 2009 by the government of Guyana in response to the Reducing Emissions from Deforestation and Forest Degradation in Developing Countries program has triggered evaluation of forest-related activities, thereby acting as a catalyst for improvements in Guyana's small- to medium-scale gold mining industry. This has also shed light on areas committed to conservation, something that has also been handled by Non Governmental Organizations. This paper compares water quality and mercury concentrations in sediment from four main areas in Guyana, two that are heavily mined for gold using mercury amalgamation methods (Arakaka and Mahdia) and two that are considered conservation areas (Iwokrama and Konashen). Fifty-three sediment and soil mercury loadings ranged from 29 to 1,200 ng/g and averaged 215 ± 187 ng/g for all sites with similar averages in conservation and mining areas. Sediment loadings are within the range seen in French Guiana and Suriname, but conservation area samples had higher loadings than the corresponding uncontaminated baselines. Type of ore and location in the mining process seemed to influence mercury loadings. Mercury sediment loadings were slightly positively correlated with pH (correlation coefficient = 0.2; p value < 0.001) whereas no significant correlations were found with dissolved oxygen or turbidity.