I found this site on line,
I found this site on line, tho their product does not seem to say the product for cats keeps flies away. You could try sending them an email tho: If your cat has a tumor, you could try the Colloidal Silver I mentioned in another recent comment to another person. It is amazing for a lot of different ailments-from very serious to not so serious. The product I have researched as being top notch is Mesosilver 20 ppm. Hope this helps