Mast Cell Tumors
Xena - the wonder dog
A couple of months ago, we noticed Xena had a lump show up one day on her upper right leg, almost by the hip joint. It was soft and moved with the skin so my husband figured it was a fatty cyst like Bogey had two years ago. He figured it was nothing to worry about. Then we started noticing a bit of a bump on her snout just below her right eye. It didn't really do anything (growth-wise) for a while but it was hard and didn't really move much. My husband said "It'll be the one on her face that gets her."
The leg bump was getting larger at a fairly steady pace but yesterday, the one on her face just ballooned up. She's squinting out of the right eye now, it's that large.
I did some research online today and I've pretty much come to the conclusion that they are mast cell tumors, which is a form of canine cancer. Xena is a boxer-mix and the stuff I've read said that Boxers and Pugs have the highest predisposition to MCTs, usually later in life. Xena is almost 8.5 yrs old, which is the time the MCTs start showing up.
Here are some of the highlights I came across in my search:
* MCTs can occur in a dog of any age, but they are typically found in middle age or older dogs, with a mean age of 8.5 years.
* When you feed a carnivore a diet based on grain, they develop various immune dysfunctions, including cancer.
* Stage I - solitary tumor confined to the dermis without lymph node involvement
* Stage II - solitary tumor with regional lymph node involvement
* Stage III - multiple dermal tumors with or without lymph node involvement
* Stage IV - any tumor with distant metastasis or recurrence with metastasis
* the danger from mast cell tumors arises from the secondary damage caused by the release of chemicals that they produce. Mast cells can release several biologically active chemicals when stimulated, among them histamine, heparin, seratonin, prostaglandins and proteolytic enzymes.
* Among the most common victims are beagles, Boston terriers, boxers, bulldogs, bullmastiffs, bull terriers, dachshunds, English setters, fox terriers, golden retrievers, Labrador retrievers, schnauzers, American staffordshire terriers, and weimaraners. Boxers are at the highest risk
* Grade 3 tumors are poorly differentiated, very aggressive, and most likely to rapidly metastasize. They carry the poorest prognosis but are fortunately the least common.
* One characteristic quirk of mast cell tumors is the tendency for them to change in size, even on a daily basis.
* Handling these tumors can cause a heavy release of histamine that results in swelling, redness, itchiness, hives
* High-grade tumors may be treated systemically with prednisone and/or other chemotherapy. Sometimes the only "treatment" is supportive care intended not to extend the dog's life but to make what remains of it as comfortable as possible.
* Dogs treated for mast cell tumors may have 3-5 radiation sessions per week for 3-5 weeks and must be anesthetized for each treatment. This may cost several thousand dollars
(My husband won't even consider this and I would tend to agree, even if it was my beloved Bogey or Max we were talking about. There are plenty of other unwanted dogs out there who could benefit from several thousand dollars and with MCTs, that money may only buy a month.)
* Prednisone (a corticosteroid) appears to be the drug of choice in treating mast cell cancer, so much so that many veterinarians will routinely prescribe several weeks or months of prednisone subsequent to surgical removal of any mast cell tumor. In the great scheme of things, prednisone is inexpensive and safe.
* If a tumor has a reasonably high metastatic potential, or if it has already metastasized, prednisone is likely to be prescribed.
* Corticosteroids like prednisone, antihistamines like benadryl, and antacids like tagamet, zantac or pepcid are often used as a matter of course after surgery and/or radiation and are routinely used to maintain comfort in dogs where the cancer cannot otherwise be treated or has spread.
* Prognosis/Grade-3 MCT or metastasis: Only 15% of dogs with Grade 3 MCT will be alive 7 months after surgery, and only 6% will be alive after 2 years. Once mast cell cancer has metastasized, dogs tend to die within 6 months as the symptoms of systemic illness (e.g., gastric ulcers) can no longer be managed and the animal loses its quality of life.
* The Grade III cases are almost always fatal. Some will appear rapidly on the face, feet or axilla and resemble insect bites.
* Treatment of Stage III (multiple dermal tumors with or without lymph node involvement) or Stage IV (any tumor with distant metastasis or recurrence with metastasis) tumors is generally palliative (to moderate the intensity of). One recommended therapy is prednisolone (2 mg/kg body wt, PO, for the first 5 days, followed by a maintenance dose of 0.5 mg/kg, daily)
* Certain fatty acids called Omega 3, 6 and 9 are required in fighting cancer. Fish oil is a good source of these specific fatty acids. We HIGHLY recommend fish oil be added to any cancer dogs diet. One 1000 mg softgel capsule per 20 lbs body weight per day is a good dose for dogs. (60 lbs dog gets 3 capsules per day).
I started Xena on 3,600 mg of Fish Oil daily, along with Benadryl and Ibuprofen. I ordered some 20mg Prednisone tablets from an online Canadian pharmacy fpr $50 USD. They're saying 2-3 weeks delivery time. *sigh*
Right now, she's still bouncy and energetic. This story of Grandma the Boxer brought tears to my eyes.
Sources: Mast Cell Tumors, Courteous Canines, Canine Cancer Awareness, Dog Cancer.net
We love you, Xena.
