Mesotheliomas are rare neoplasms that originate from ectodermal cells that line the body cavities. Mesothelium is a membrane that forms the lining of several body cavities: the pleura (thoracic cavity), peritoneum (abdominal cavity including the mesentery) and pericardium (heart sac). This lining consists of a single flattened layer of ectodermal cells that line the aforementioned body cavities as well as the tunica albuginea of the testes.
Mesotheliomas are the result of abnormal division and replication of mesothelial cells, and their migration to other sites in the body. This cellular behavior can occur in the thoracic cavity, the abdominal cavity, the pericardial sac around the heart, and for male dogs, in the scrotum. The resultant tumors will often displace internal organs, causing gastrointestinal or cardiac symptoms. Mesotheliomas also produce a lot of fluid, making microscopic (cytologic) examination of fluid samples an extremely relevant diagnostic tool.
Certain breeds are predisposed to this condition including german shepherds, irish setters and Bouvier des Flandres.
Common symptoms associated with this condition are
Trouble breathing
Muffled heart, lung, and abdominal (ventral) sounds
Abdominal enlargement/swelling with fluid build-up
Large scrotum
Exercise intolerance
Fatigue
Vomiting
