Mast cell tumors represent the most common malignant skin tumor in the dog. This review outlines the incidence, etiology and clinical signs of mast cell tumors. Diagnostic tests, staging and treatments are also discussed.

ABSTRACT

Variations of age and total length of Sotalia guianensis from the state of Espírito Santo, Brazil, were evaluated. Specimens were found stranded. Age and total length of 44 Guiana dolphins were assessed based on tooth analysis. Age varied between 0.5 year and 33 years (mean = 8.23 years). Most specimens were between zero and 6 years old (47%). Total length varied from 119 cm to 198 cm, with mean of 172.52 cm. Asymptotic length was reached at 185 cm and approximately 5-6 years of age. Mean total length and age were higher than in other regions of the distribution range of the species. Nevertheless, more studies have to be carried out to evaluate the morphological variations in S. guianensis populations in the study area and Brazil.Keywords: Guiana dolphin, age, total length. Variação etária e de comprimento total de

The estuarine dolphin, Sotalia guianensis, is one of the most abundant cetacean species in Brazil. Determination of age and of aspects associated with the development of this species is significant new studies. Counts of growth layer groups in dentin are used to estimate age of these animals, though other ways to evaluate development are also adopted, like the measurement of total length (TL). This study presents a procedure to evaluate the development of the estuarine dolphin based on the ossification pattern of forelimbs. Thirty-seven estuarine dolphins found in the state of Espírito Santo, Brazil, were examined. Age was estimated, TL was measured and ossification of epiphyses was examined by radiography. We analyzed results using the Spearman correlation. Inspection of radiographs allowed evaluation of the significance of the correlation between age and development of the proximal (r = 0.9109) and distal (r = 0.9092) radial epiphyses, and of the distal ulnar epiphyses (r = 0.9055). Radiographic analysis of forelimbs proved to be an appropriate method to evaluate physical maturity, and may be a helpful tool to estimate age of these animals in ecological and population studies.