Recently, I was asked whether dogs can get mesothelioma like people. The answer is yes dogs can get mesothelioma But there is no link to asbestos exposure and mesothelioma in dogs. Mesothelioma in dogs can arise from the mesothelial cells of the pleura, pericardium, or peritoneum and can be malignant or benign. Mesothelioma is emerging as an increasingly important cause of pericardial effusion. Mesthelioma can occur in any breed of dog. Mesothelioma should be considered as an underlying cause of any dog found to have pericardial effusion. Diagnosis is made by examining the tissue covering around the heart. Mesothelioma can spread throughout the thoracic cavity. In people, mesotheliomas are frequently associated with exposure to asbestos. There has not been link to mesothelioma and asbestos exposure in dogs, although the studies of asbestos and mesothelioma in dogs is limited. Histologically mesothelioma can be fibrous or epithelial; in humans both are seen but pleural mesotheliomas in dogs are predominantly the epithelial type. Metastasis to other intrathoracic organs such as the myocardium, tracheobronchial lymph nodes, and lung is common. This tumor may also invade the diaphragm and enter the abdomen. As mentioned above diagnosis of mesothelioma, must be done on tissue rather than fluid because it is hard to differentiate neoplastic mesothelial cells from reactive mesothelial cells. In human medicine, pleurodesis is often used to decrease the incidence of malignant mesothelioma effusions. Attempts at pleurodesis in dogs have been unrewarding and are not recommended as a treatment method. More research is necessary to narrow down the cause of mesothelioma in dogs.