Frequently Asked Questions

Department of Radiation Oncology



Will the radiation treatments burn my pet’s skin?

Radiation does not cause thermal injury to the skin. What we may see with radiation patients that have a tumor near the skin’s surface is called “moist desquamation.” Think back to a time that you skinned your knee on the sidewalk when you were playing as a child. The healthy, pink tissue that was exposed gave off a fluid (plasma) that hardened into a crust (scab). With radiation therapy, there is a mild amount of inflammation associated with this same change in the skin surface. Patients benefit from an oral anti-inflammatory medication, which we start at the beginning of treatment.

Moist desquamation is usually observed near the end of radiation therapy, and is generally healed within 2-3 weeks after treatments have completed. It is important to note that this skin effect only happens when surface tissues are targeted for radiation therapy – the same is not true for skin over tumors located deeper in the body.

Is radiation therapy painful?

Radiation therapy is not painful. The overall radiation dose prescribed is divided into small, daily or weekly treatments. Because there is no pain associated with the treatments, we use sedation or light anesthesia only to ensure that there is limited movement during treatment.

Will radiation treatment of my pet have effects on me/my children?

Unlike radiation treatments for a small subset of human and animal cancers, where radiopharmaceuticals (radioactive molecules in liquid form given by injection) are used for treatment, the radiation treatments at VRC are given using “external beam radiation.”  These treatments are provided by a machine called a linear accelerator, which is a high-power x-ray tube. Similar to creating x-ray pictures, radiation is only given to the patient when the machine is on. When this machine is off, there is no radiation emitted, and no radioactivity is found at the treatment site on the patient. Feel free to cuddle and play with your pet just as you did before (s)he started radiation treatment.

Can my older pet tolerate multiple days of sedation/anesthesia?

A common phrase in veterinary medicine is “age is not a disease.” As we are more likely to diagnose cancer in older patients, the majority of patients undergoing radiation treatments are advanced in age. Checking baseline blood work is one measure we take to assess individual blood cell lines and organ health, ensuring our patients stay safe during procedures. More than likely, if the results are within normal ranges, your pet will be able to handle the medications we prescribe.

To further ensure safety under sedation or anesthesia, it may be recommended that your pet have chest x-rays or a heart ultrasound. Between the blood work and imaging studies, even mild changes that may be detected in the organs do not prevent treatment, as using sedation or anesthetic medications that are friendly to specific organs is easily accomplished.

Will my pet become sick from radiation therapy?

Radiation therapy is a localized treatment, so your pet should not experience vomiting, diarrhea, lethargy, or other signs of general illness as a direct result of the radiation treatments. Because of daily sedation or anesthesia, your pet may become tired near the end of each week during treatment. Some patients may seem a little tired and play less for 2-3 weeks after radiation therapy; however, most clients tell us that their pets act like a puppy or kitten again, even during treatment.

How long do radiation treatments take?

Overall treatment time is only 10-15 minutes. However, patients typically spend 1.5 to 2 hours with us each day of treatment. During this time, your pet received a daily physical exam, including an updated body weight assessment, a radiation treatment, and supervised recovery from sedation of anesthesia. If the location of your home does not allow for daily travel to our hospital, we offer boarding options for your pet.

What is the difference between definitive and palliative radiation therapy?

Definitive radiation therapy is given as daily treatments over 16-20 days, Monday through Friday. This protocol includes a higher overall dose of radiation for better tumor control, and for certain cancers, a cure.

Palliative therapy is reserved for patients who have a cancer that cannot be completely cured due to a variety of reasons. The goals of palliative radiation therapy are to reduce pain, decrease tumor size, and improve the quality of life for the time an animal has left. Palliative radiation therapy is given as once weekly treatments over four weeks, or daily treatments during one week. The overall prescribed radiation dose is lower as compared to definitive radiation, and palliative radiation offers a chance to treat with positive benefit when a complete cure is not possible.