Radiation Therapy for Dogs

In addition to surgery and chemotherapy, radiation therapy is a common cancer treatment for dogs.  Depending on the type of cancer diagnosed, It can be used alone, in combination with chemotherapy, or used post surgery to kill any remaining cancer cells.  While it is often used to try to cure cancers, it can also be used as a palliative treatment — to reduce pain or discomfort caused by the cancer.  This is especially true in the case of osteosarcoma, or bone cancer.

Radiation therapy is often used for cancers that are localized (have not spread to other parts of the body), but which cannot be surgically removed, or in cases when surgery has been performed, but clean margins could not be obtained, and the oncologist has concerns that some cancer cells may remain.  Half-body radiation may also be suggested for dogs with lymphoma.  In this case, half of the body receives radiation therapy at the start of cancer treatment, and the other half of the body about one month into treatment.  By radiating only half of the body at a time, the bone marrow is not completely destroyed.  In the case of bone cancers, radiation therapy can help to reduce pain, although it may not extend life.

In addition to bone cancer and lymphoma, other types of cancer that may be treated with radiation therapy include nasal tumors, oral squamous cell tumors, brain tumors, soft tissue sarcomas, some melanomas and mast cell tumors.

Side effects of radiation treatment usually take a while to show up, but once they do, will usually last a few weeks. Typical side effects include hair loss at the radiation site, skin discoloration (like a sunburn) and irritation, general fatique and loss of appetite.  Other side effects are are usually specific to the area being treated (i.e. nausea and vomiting if the abdomen is treated, chronic dry eye if the eyes are near the treatment area, etc.)

Before deciding whether or not radiation therapy is right for your dog, there are four important things to consider:

1. Your Dog’s Overall Health.  Hopefully an ethical veterinarian will not suggest radiation treatment unless your dog is a good candidate for the treatment.  However, you know your dog best and are ultimately responsible for making these difficult decisions.  Because radiation requires short periods of anesthesia each time, as the dog needs to remain perfectly still during treatment, you must consider whether or not this is something that your dog can handle.  While dogs are very closely monitored throughout each radiation treatment, there is always some degree of risk involved in anesthetizing a dog (or person).  Also, consider your dog’s emotional health — will they be able to deal with the frequent trips in for treatment or would this be too traumatic for them?

2. Your Dog’s Age and Prognosis.  If your dog is elderly, or if the cancer being treated may have metastasized or cannot be cured, even with aggressive treatments, then the physical and financial costs of radiation treatment may not be worthwhile.  However, if pain management is the goal, and time and money are not a barrier, radiation treatment may be an excellent option for some types of cancer, even if it cannot be cured.  Generally, radiation therapy is offered for pets who are expected to live at least one year beyond treatment.

3. Location of the Treatment Facility.  Radiation therapy requires highly specialized equipment and is not widely available like chemotherapy.  Facilities that offer half-body radiation therapy are even more rare.  Since most dogs require treatments 5 days a week for for 2-5 weeks depending on the size and location of the tumor, a facility that is hours away may not be feasible unless you can arrange for an extended stay near the facility.

4. Cost.  It’s a harsh reality, but no matter how much we love our canine companions, we sometimes cannot manage the financial burden of aggressive cancer treatments.  While pet insurance can help reduce the out-of-pocket expense of radiation treatment, it is still a very expensive proposition.  Aside from any travel or hotel costs that you may have to spend to bring your dog to a treatment facility, a typical radiation treatment protocol will cost somewhere between $900 and $3500 dollars. 

CLICK HERE to watch a video from the Cornell University School of Veterinary Medicine showing a dog named Triton going through radiation therapy.

Other links related to veterinary radiation treatment:

Listing of Veterinary Radiation Oncology Facilities from the Veterinary Cancer Society

“A Look at Radiation Therapy for Pets” from Radiology Today

 “Radiation Therapy” by Dr. Holly Nash, DVM, MS from PetEducation.com