My 10 year old lab has 2 grade 3 mast cell tumours, she has had surgery but they came back. She is now under an oncologist undergoing chemo (intravenous Vinblasten and Predislone) She was great after the first dose but has been really sick and off her food after the second. The tumours don't seem to be shrinking so my own vet suggested I ask about Masivet. the oncologist said there were other drugs we could try, I guess these are intravenous as well. The discussions on here about Masivet sound good but the price is incredible and I don't want her to go on feeling ill all the time. If we try Masivet does anyone know if she would stay on it for as long as she lives or is it like the other chemo for a limited time???? Help any advice it's so hard to know what to do for the best