Mast cell tumors in a dog

February 16, 2013 4:50 PM

The cytology showed up that my dog's tumor has mast cells.

She is getting the tumor excised on Friday. I'm freaking out a little bit. She has another tumor that is definitely a lipoma. I am very medically-savvy in humans, but not in dogs. Would you please share your experiences?

posted by kamikazegopher to health & fitness (7 answers total)

Not a dog, but our elderly cat had mast cell cancer. We chose not to treat it, due both to his advanced age (around 14-15 years old) and the cost. He lived a happy 18 months longer, still loving life, just slowing down a bit. Then started a steep decline and we made the decision to put him down. Sorry that you're experiencing this.
posted by BlahLaLa at 4:57 PM on February 16

From someone who is currently living in Dog Cancer Land, I am (almost) jealous of your dog's diagnosis. A lipoma is not a big deal. The big issue with a mast cell tumor is the ability to get clean margins because it is a very locally invasive kind of tumor - where is the tumor located? Will they be able to get enough tissue to get clean margins?

My dog has another kind of locally invasive tumor, a fibrosarcoma. It is on his snout, and the vetrinary surgeon I took him to did not think that surgical removal would be successful. My dog is old for a large dog (almost nine), and this tumor will eventually kill him. How soon? I don't know.

If your vet is confident that surgical removal of the tumor will be successful, then yay! Mast cell tumors and lipomas are very common in dogs. The key information that you'll need after surgery is the analysis of the removed tissue. If there's still cancerous tissue around the edges, ask your vet what your next step should be.
posted by ablazingsaddle at 5:10 PM on February 16

My four year-old golden retriever had tumors that turned out to be mast cell cancer in two locations. Since she was four, we went for surgery. She did great. I think (this doesn't make sense to me medically, but it is what I remember) we also put her on prednisone about then, which made her insanely hungry and altered her joix de vivre somewhat for the worse. When she was thirteen, she had mast cell cancer again, only this time apparently more widespread. Since she was an old lady by then, we did not treat it, and the course was similar to what BlahLaLa described -- she lived about another eight months, slowing down slowly. She also became frankly a little crazy -- would go sleep in my neighbors koi pond in December, for example, and wanted to be outside in the cold *all the time* which was not characteristic of her at all (had been previously very much a creature of domestic comforts). In the last few days she did not want to eat and would start drinking, but then stop, as if she couldn't do it. My whole family flew home from different corners of the country and we spent a nice last day with her and then had her put down at home.

The next golden retriever went from old but healthy to dead in about a week (also cancer) -- in retrospect, I am glad that I had the eight months of knowing the first one was dying to get used to the idea and to make her last days as happy as possible and to have the putting-to-sleep bit be a planned event and not an emergency.

If your dog has limited mast cell, surgery should fix it. The lipoma is nothing -- benign tumor that many dogs have with no consequence.
posted by half life at 7:10 PM on February 16

This blog journal of a dog's mast cell tumor treatment has lots of good info.
posted by peakcomm at 12:27 AM on February 17

The tumor is just under the skin on her flank. The vet seems very confident of being able to get clean margins, but she was also confident that both tumors were lipomas, so I'm a bit shaken. Thank you all for your answers so far.
posted by kamikazegopher at 12:50 AM on February 17

I lost a dog to this because the location didn't allow for enough margin for surgery. I'm happy you don't have this problem.
posted by Raichle at 7:42 AM on February 17

The surgeon was able to get clean margins, but my dog's skin is stretched very tight (it would have been easier if she was overweight!). The prognosis is very good. Her stitches unraveled and had to be replaced with staples, so she is Frankendog, but that is the least of our worries. Thanks to all who commented.
posted by kamikazegopher at 1:44 AM on March 2