The side effects of palliative radiation therapy, as opposed to definitive radiation therapy meant to help cure a cancer, tend to be minimal because the total dose is “pretty low,” says Tufts radiation oncologist Michele Keyerleber, DVM, DACVR.
“The goal is to have no side effects,” she stresses, since the aim is to get a dog more comfortable in the limited time she has left, not to eradicate every last cancer cell. And two thirds of dogs do, in fact, experience absolutely no side effects. “But it’s a bit unpredictable, like for people,” she adds. “Each dog has an intrinsic sensitivity to radiation that you can’t know in advance.”
Fortunately, for the one third of dogs treated with palliative radiation therapy who do experience side effects, they’re generally no worse than mild to moderate and may include hair loss, redness to the skin, and in rare cases, a kind of moist ooziness to the skin or inflammation of the oral cavity or throat if those locales are within the radiation field.
Along with being mild, side effects tend to be transient, lasting a few days or a week at most, after which a dog heals and simply feels less cancer pain.
