My daughter is a special ed teacher and the dog is a therapy dog for the elementary school where she teaches. The dog (a female) is taking palladia along with benadryl which is for the effects of the mast cells, and some anti nausea drugs that have kept her from becoming ill from the treatment. The palladia is a pill given every other day at the moment.
She had a problem with her paw that wouldn't heal and after months of trying to get over it, the vet did a culture and biopsy to see if that would give them a clue. It turned out there was an unseen Mast Cell tumor in the paw which never ballooned to the outside because of the weight of the dog on the paw. Once they learned about the cancer, they sent her to Purdue for an ultrasound and aspirations of the liver and spleen to see if it had spread. The ultrasound didn't show any other masses, but there were Mast Cells in her spleen. Mast cells are normally found in their bodies, so they couldn't be sure if it had spread, but they assumed it had considering the amount of time that elapsed after the first problem with the paw and the discovery of the tumor.
After about two months on the palladia and other meds, her paw has healed. We took her back to Purdue for another ultrasound and aspirations. Once again, the ultrasound showed nothing and the aspirations had no Mast Cells either. That doesn't mean there are no mast cells there, because they take such a tiny amount in the aspiration, but we took it to be good news.
She is still on the same dose of palladia and doing well. It has given her some quality time and she seems happy and comfortable so far.
If you have any questions, I'll be happy to answer them.