Peritoneal Mesothelioma in Cats

Lili Duda, VMD
Last Modified: November 1, 2001

Dear OncoLink "Ask the Experts,"
My cat has a peritoneal mesothelioma. My vet says that this pathology is very rare in cats and is studying a protocol for the chemotherapy (possibly intracavitary chemotherapy). My vet attended two dogs with cisplatin, with good results, but this drug is lethal for cats. Can you send me information about possible therapies for cats? And what do you think her prognosis is like?  
A. S.

Lili Duda, VMD, Editor of the OncoLink Veterinary Oncology Section, responds:

Dear A.S.
Mesothelioma is a rare tumor in cats, with very little in the veterinary literature. It is a diffuse tumor of the lining of the body cavity. The tumor cells produce fluid which accumulates, in the abdomen in this cat's case. Treatment efforts are aimed at palliation (controlling the clinical signs)—there is no cure for this tumor. In dogs (and people) the chemotherapy drug cisplatin is placed into the body cavity to try and decrease fluid production. Cisplatin is fatal to cats. Carboplatin is a newer drug related to cisplatin and it is safe in cats. The intravenous dosages are well worked out; however, I am unaware of any reports describing intracavitary use in either dogs or cats.

We are sorry to say that, unfortunately, the prognosis is very poor.

Thank you for your question. Best of luck.