Malignant Sclerosing Biphasic Mesothelioma: first repport in a dog.

Malignant Mesothelioma is a malignant tumor arising from the peritoneum, pleura or pericardium. It's rarely reported in dogs. Currently, there are two classifications of neoplasia: one for human medicine and other for veterinary. A 10-year-old female mixed-breed dog with bulging abdomen for 2 weeks and achesia for 1 day, was diagnosed with ascites and dirofilariasis and treated. On the first day, the animal weighed 32.5kg and, after drainage of cavity fluid, it weighed 27kg. Even after treatment, the animal's condition did not improve and euthanasia was performed. The body was sent for necroscopic evaluation. The morphological diagnosis comprises malignant mesothelioma, been with both mixed and sclerosing type. This is the first worldwide case reported with all this characteristic.