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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

Why Would Anyone Choose Chemotherapy?

Updated: October 10th, 2018

Very few people overall will opt for chemotherapy for their dogs with cancer.

This is interesting, because in human medicine it is widespread.

It would seem that fear of life quality loss, expense, side effects, and lack of cure in true malignancy are the main deterrents.

However, there are some reasons why some do opt for chemo in treating their four legged family members.

Some cancers actually respond pretty well.  By response, I mean that the signs of the cancers go away and the dog, for all intents, is normal again.

Although this is temporary, in some cases the remission can be very long, even years in the best cases. Granted, these long remissions usually arise when dog guardians combine the chemo with other steps in full spectrum care.

One of the cancers that really responds well is lymphosarcoma.  Over 80% of lympho cases will get what is called a first remission, meaning the cancer signs and symptoms disappears for a period before needing a second round.

Many dogs handle the chemo well.  The number of dogs that are able to deal with the toxic effects of these drugs does indeed go up if certain steps are taken.  These are discussed at length in The Dog Cancer Survival Guide.

The best way to cure a true malignancy is to remove it with surgery.  However, not all cancers can be removed.

We call these cancers “non-resectable”.  A non-resectable cancer takes several forms. Most of these occur in masses (tumors) that require injuring  vital structures to be removed successfully.

Other times, a cancer cannot be removed because it is found in the circulation (cancer cells flowing around the body).  Lymphosarcoma or leukemias occur here.  Also, cancers that have spread into the circulation from a growth fit in this class.

There are some tumors that spread into the surrounding areas in the neighborhood of the tumor. One cannot see the spread with the naked eye. However, when the surgery takes place, cancer cells are left in the surrounding neighborhood.  Many of these cannot be removed and chemotherapy is one option.

Cancers that spread into the surrounding neighborhood of a growth are called “locally invasive”.  Some include fibrosarcomas, squamous cell carcinomas, some hemangiosarcomas, and more.

Finally, if a tumor arises in one location and then shows up on another location (metastasis), chemotherapy is often considered.

The most important thing to remember is to arm yourself with the facts.  Find out the success rates of the chemo, how many respond, for how long, what is involved, the cost, rough incidences of side effects, and what you can do to decrease toxicities.

All my best,

Dr D

Leave a Comment

  1. Carol on February 23, 2010 at 8:19 pm

    Hi Dr. D.
    Huckleberry, husky/lab eight years old, has been diagnosed with a very large (grapefruit size) fibrosarcoma in his throat tissue confined only to his throat at this point. He has had intravenous chemo which shrunk the tumor somewhat and has helped his breathing. It’s been two weeks, we’re headed back in two days for the next chemo, but the last two days the tumor has started to grow again and he is sleeping alot and doesn’t seem to feel as well. Although when we mention walk he’s up and ready to go, loves eating and drinking water. He is on Rymadyl, antibiotics (he has a tube drain in the tumor) we’re feeding him meat, rice, mixed with veggies, no corn no wheat. The Vet put him on glutamine powder, omega 3s and vitamin E, and I have him on tumeric. I’m thinking about putting him on mushrooms as well. What other recommendations might you have for him? And is it normal that the tumor would start to grow again so quickly between treatments? Thank You! Carol

  2. Susan Cheatwood on February 23, 2010 at 8:10 pm

    My 12 year-old red hound was diagnosed with a transitional cell nasal tumor a few weeks ago. A CT Scan was done in hopes of doing Stereotactic Radiosurgery, but the oncologist felt the tumor was too large and advised palatve radiation therapy for 2-4 visits. The tumor has not invaded the cranium or nasal bones, yet. We plan to start the radiation therpay Monday. Have you had any experience with this type of tumor? What else can I do to support her? She has developed inappetite which the oncologist did not feel were related to the tumor. It is hard to get her to eat and she only eats dog biscuits or a chewy surgical supplement my vet had. I am afraid to try chemotherapy with her lack of appetite and am not sure it will help. Thank you for any experience with this type of tumor.

  3. Stacey on July 21, 2009 at 5:45 am

    My 6 year old siberian husky was diagnosed with high grade malignant schwannoma(Nerve sheath cancer)…the tumor started on her stomach and by the time we knew she was sick she had four more on her liver. She had surgery to remove the three tumors that we operable. Unfortunately two on her liver could not be removed. Our only option was chemotherapy to keep the two remaining tumors in check. I was hesitant but she handled chemo extremely well…very little side effect…a bit of diarrhea handled with meds. Her first round over we tried oral daily chemo pills which did not seem to work as well…one tumor has gotten bigger and there are four other small ones spreading to her bladder and kidney. We are trying another round of chemo…oral pills given every three far so good. Tamaiijja is in great spirits…happy and sweet as ever. As long as she feels this good we will continue her treatment. She deserves all we can do for her. She was a chained dog the first year of her life..ran away only to be hit by a car and lose her leg. We adopted her 5 years ago and she is the light of my life…sweetest, most loving dog ever. She also did therapy dog work up until her diagnosis. We had no pet insurance but the sacrifices we make to pay for her treatment are so worth it. We just enjoy every moment we have left with her no matter how long it may be and make sure she is comfortable, happy and has a great quality of life.

  4. Melinda Ramsey on July 21, 2009 at 5:30 am

    Can anyone advise on Osteosarcoma of the oral cavity on a mixed breed female, spayed German Shepherd? She is about 7.5 years old and had this diagnosed July 3. The location is posterior to her upper right canine. I just returned from NC State last night for a consultation. The odds of her surviving for a year are about 45% if we go with a parital maxillectomy. I’m so torn as to how to take care of my girl. Her health is excellent otherwise but my concerns are that if we operate and put her through the surgery and chemo and the odds are that low, is it causing unecessary suffering for her to have to go through knowing that osteosarcomas are not typically given a good prognosis due to metastasis. At this time we were told they did not see any signs elsewhere in her body, but there may be some abnormality in her spleen. We have not heard back yet on that. I will do whatever i can to make her as comfortable and happy as possible, but i’m really struggling with this decision. ANY INSIGHT???

    • Dr. Dressler on July 26, 2009 at 8:19 am

      see if the oncologists you are working with has access to open cell polylactic acid polymer impregnated with cisplatin. This is an sponge implanted in muscle that delivers cisplatin over a long period of time. It has been looked at experimentally in publications. I have not been able to find a source. It increased survival times of tumors similar to your dog’s significantly. I will address this in the recorded webinar:

  5. Gwen Jones on July 20, 2009 at 5:30 pm

    To Anyone Considering Chemotherapy for their Dog,

    We opted for chemo with our Border Collie, Molly who was diagnosed with high-grade malignant lymphoma. It was a non operable tumor in her lower GI tract; the severity of which was unknown until the surgeon had split her pelvis in four places. The diagnosis and surgery where over a year ago, in June of ’08, and I’m happy to say that she is completely tumor free and has been back running agility with her mom!

    The chemo was tough, we had her on the Madison, Wisconsin protocol and had to adjust some of the drugs, (which are measured by the dog’s weight) because they were making her so sick. She lost a lot of hair too, but has since grown it back with a vengeance! We aren’t sure if we would put her through chemo again, knowing definitively that the tumor will come back, but we had to try it once, and keeping our fingers crossed, the chemo seems to have done the trick.

    By the way Molly is also a rescue from hurricane Katrina, so I think this little dog is blessed somehow to beat the odds against anything mother nature throws at her!

    Good luck to all of you facing this terrible disease.

    Gwen, Dustin & Molly

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