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

Things You Need To Know About Radiation for Dog Cancer

Updated: November 27th, 2018

This is a continuation of the previous blog topic, radiation therapy in dog cancer.

We looked at some benefits of radiation previously, both in terms of life quality and lifespan.

This time, I would like to look at some of the downsides.  I am not interested in painting a darker picture than is necessary.  This is a treatment where a rationale approach in needed, where good and bad are evaluated.  As an owner and guardian of your dog, you should be advised of things so you can make educated decisions.

Radiation therapy is no joke. Each treatment requires general anesthesia, and protocols for designed for cancer remissions involve multiple treatments each week, sometimes even daily. Multiple rounds of general anesthesia should be taken into account when making a decision about radiation, especially in senior dogs. Most vets would agree that an aged canine and 30 rounds of general anesthesia may not be a good mix.

Palliative treatment, radiation designed for the comfort (pain control) of the dog, is less frequent, perhaps weekly for a month or so. This seems a bit “easier on the system” overall.

The radiation in the beam, if it contacts other living tissue, will damage it as well. Sometimes there is radiation scatter, which is where the beam directed at the tumor actually ends up hitting a bit of normal (non cancerous) body tissue.

There can be some side effects that may be seen immediately following treatment, when the beam contacts normal body parts.

The skin can get a little inflamed, similar to a sunburn. There may be nausea, vomiting, diarrhea, and loss of appetite. If radiation contacts the mouth, irritation and sores may occur within mucus membranes lining the mouth. This can be painful and require care. If the beam or scatter contacts the gland that makes tears to lubricate the eye, injury can occur to the glands.  This  requires lifetime lubricating ointment to be put in the eyes. Similarly, the lining of the lungs can become damaged if they are exposed to radiation.

All of these effects can occur within days or weeks of radiation treatment and examples of acute toxicity.

Get a copy of the Dog Cancer Survival Guide to learn more about Dog Cancer and Radiation

Radiation consequences can occur years later…delayed radiation toxicity. This can include injury to kidneys, nerves or spinal cord, and ligament damage.

A bizarre delayed toxicity form is the development of new cancers, as a consequence of the radiation. This is documented with cases of osteosarcoma (bone cancer), bladder tumors, and connective tissue tumors.

Take home message? Radiation is not a minor therapy. Consider it carefully. Be advised if you have a young dog that you are considering radiation for, you may see delayed toxicity, years later but during the dog’s lifespan, even in the form of new cancers.

Leave a Comment

  1. Jackie on January 20, 2023 at 4:01 pm

    Our 9 year old yellow Labrador has been initially diagnosed with hemgioperiocytoma. We are waiting for final pathology. He is scheduled for surgical removal of the mass on his hind right leg. It’s about the size of a golf ball. Came on very sudden. Wondering what your recommendation would be post surgery??
    Thank you

  2. Richard Gomez on December 4, 2022 at 9:25 pm

    Dear Dr. Dressler,
    Does there exist an industry standard or requirement to protect canine body parts from radiation exposure as with human medicine.? My veterinary practice X-rayed my Toy Fox Terrier’s lungs, heart and pelvis and he suffered from side effects that caused an emergency visit. He was paralyzed (my opinion) and since his heart is enlarged, it impinges upon his trachea. He was barely breathing. The Veterinarian’s diagnosis = “Old dog vestibular brain stem or cerebellar lesion.”, which I think is a cover for radiation exposure, meaning excessive and for not protecting my dog.
    At the time of the emergency, she said that my dog had vertigo (my word, she said “dizzy”) and that he was not “oxygenating well”, meaning hypoxic, ref my comment about Chura’s tracheal impingement. All this from radiation to the brain and the practice did not protect Chu’ra Such is why I ask about industry standards and or requirements. Additionally, are veterinary practices required to hire X-Ray technicians or are Veterinary Technicians and/or Veterinarians trained on X-Ray equipment usage.? Thank you for your time, knowledge, and wisdom.
    Best Regards,
    Richard Gomez
    USAF Veteran, MBA (Aviation)

Scroll To Top