Cat has mast cell tumors and we seem to be running out of options.

July 20, 2021 11:28 AM

Poppa is almost 15. A while back he had what I thought was a scratch on his hind leg that kept getting irritated since he would jump from cabinets over the fridge to the countertops below. It wasn’t healing so I took him to the vet and an allergist.

He was also pulling his hair out and scratching. I thought he might be allergic to chicken, turkey, duck and changed his diet. He only gets wet food since he has issues with constipation. The allergist did some tests and informed us that the culprit was mast cell tumors and yeast. She prescribed a foam that was supposed to help with the yeast and itchiness. He hated it but it seemed to stop the itching and hair-pulling. We had the mast cell tumors removed and the prognosis seemed positive.

Then randomly he started pawing at his mouth around dinner time. We thought it was his teeth or related to his food. We took him back to the vet and even went to a dental specialist who did a scan of his head and mouth area. No issues. He's had xrays and ultrasounds and cat scans and he does not have any internal tumors or other issues. It turned out to be related to the foam we were putting on him for the yeast! So we stopped using that and he stopped pawing at his mouth completely.

Unfortunately, a few months after the surgery, we started finding more tumors. We saw the allergist again and she confirmed that they were mast cell tumors. The first vet who removed the initial mast cell tumor said that it didn't make sense to remove them all since they would just keep coming back and he had too many at this point. We are now taking him to an oncologist. He put Poppa on prednisolone which seems to help with itching. But the tumors are still popping up. A little over a month ago we tried Lomustin and he didn’t have any bad reactions but the tumors aren’t reduced. The oncologist decided it didn’t make sense to give him another treatment. He suggested a last option of Palladia. We have him one treatment on Friday and it seems like it messed him up. He was not feeling well and threw up a couple of times. He still isn’t how he was pre Palladia. We decided not to give it to him again. The oncologist said that if this didn’t work we would have to focus on palliative care. Right now we are just giving him his usual doses of prednisolone and fluoxetine, miralax, and l-lysine.

We moved in March and since being in the new place he primarily stays in the kitchen. Either on the counter or in a cabinet. He doesn’t really venture to other rooms in the house. He used to come to bed in the evening regularly and would hang out with us on the couch. When he is on the floor he runs really quickly. Maybe he doesn’t like the hardwood? This seems like another mysterious thing. When he’s on the counter he walks fine and jumps from surface to surface with no issues. He was also very vocal and eager to eat before the Lomustin.

I know he isn’t going to live forever. Right now I just want to do the right thing for him. There doesn’t seem to be a lot of information on cats with multiple mast cell tumors on their skin. Most of what I found was about internal tumors or dogs. Has anyone dealt with this before? Are there some other treatments options that we have missed? I feel like I will have to euthanize him soon if he doesn’t get better and the palladia treatment just shortened the time frame. I don’t want to let him go before I have to but I don’t want to keep him around to be miserable and suffering.

posted by mokeydraws to Pets & Animals (5 answers total)

I think this is what my cat had - not multiple tumors, but one very large tumor on her leg. I was given the option of having the leg amputated, but since she was elderly, I didn't think this was a good idea.
The problem we ran into was that the tumor would start bleeding, and the vet told me that if it started bleeding severely, I might have to take her into emergency. Now this cat hated getting into the car more than anything - I ended up hiring a mobile vet so I didn't have to have her suffer in the car (best idea ever - wish I'd thought of it years earlier). What I didn't want to risk was having her last moments include a horrible (for her) car ride followed by a terrifying visit to the vet's office because I couldn't face having her euthanized.

So I'm raising this issue as something to think about - is there a possibility of waiting making this turn into an emergency situation that will traumatize your cat? Avoiding that was why I decided to have her euthanized. It was heartbreaking and awful for me, and I cried and cried, but she was at home in her favorite chair on her special cushion when she died.

Good luck with this decision. It is hard, hard, hard.
posted by FencingGal at 11:43 AM on July 20, 2021 [12 favorites]

I'm very sorry you're going through this. We did too, when my all-time favorite cat had mast cell cancer.

Given everything you describe, if it was my cat I would just focus now on the things that make Poppa happy. His favorite treats, the most comfortable-possible setup in the kitchen for him, no more stressful vet visits. I'd stop administering any med that doesn't clearly provide pain relief.

I would use this time to research home euthanasia so he never has to go to the vet again. The home euthanasia vets I've encountered (over many, many years of owning pets) are gentle and are aware that you may not know right now exactly when you'll need their services. Most are set up to be able to offer same-day or next-day services when you're ready.
posted by BlahLaLa at 12:03 PM on July 20, 2021 [12 favorites]

Unfortunately, there really is no "treatment" for mast cell tumor. It could be considered an autoimmune disorder since mast cells are basically white blood cells that react to allergens, and when they go "bad" they dispense chemicals that actually cause the symptoms they are meant to internally treat. Any "treatment" you see is only managing the symptoms. There is no cure, sorry to say.

Prednisolone is basically a strong steroid and it can sometimes bring some cells under control. Lomustin is a chemotherapy drug. Palladia is for treating mast cell tumors in dogs and only approved by FDA for dog use, IIRC. Trying it on cats is pretty much a last-ditch off-label use.

The only thing you can do now is managing your feline's "quality of life" by giving him/her favorite stuff and decrease his/her stress, and one day, make the decision that no pet parent would want to face. If you see more symptoms, your vet can probably get you more "management" medicine for the symptoms while weighing the risks.
posted by kschang at 12:52 PM on July 20, 2021

A friend of mine had her very old and ill cat euthanized by a vet who did a home visit. When the time comes, there are vets who will do this.

I’m sorry you have to contend with this,I know how hard it is.
posted by thelonius at 3:13 PM on July 20, 2021

Seconding home euthanasia when it gets to that time. I've had to have it done three times. It's bad, but much better than taking the animal to the vet for the end.

Sorry you're going through this. You are obviously a good pet owner, and you are doing everything right.
posted by SoberHighland at 3:15 PM on July 20, 2021 [1 favorite]