Dogs and cats age faster than you anticipate. The concept of “dog years” is half mythology, but it was created for a legitimate reason—to help yougrasp the idea that your 2-year-old is actually not a toddler, but a full-grown adult. Your twelve-year-old still gets treated like a child, even though his daily life is a pretty close match for your grandfather’s. The entire existence of a dog or cat slips by in a decade—or two, at most—so pet owners (and their veterinarians) are faced with more than their fair share of old age maladies. One of the common ones is cancer.

Many pet owners view cancer as a death sentence, but our options for engaging with it are not nearly as limited as they used to be. Veterinary surgerymay not have changed much in recent years, but chemotherapy has advanced dramatically in its safety and efficacy. Unfortunately, though, “chemo” is a word that turns most people’s hearts to stone. I really have to be very cautious about uttering it in the presence ofpet caregivers, because it usually shuts down the conversation and sends them moving towards the door. In human illness, the concept of cancer-fighting drugs has a terrible reputation, evokingimages of hair loss, weight loss, exhaustion, and nausea. Chemotherapy in the dog and cat, however, has nothing in common with this picture.

Cancer treatment is notoriously difficult in any species because the problematic cells have arisen from normal cells. A successful therapy must make the fine distinction between aggressively multiplying cells and normal, law-abiding ones, or else it will have a lot of bad side effects. The newest chemo options, like vaccines and monoclonal antibodies, are very safe for the patient. They utilize the immune system, which is smarter than any chemist, to discern which cells are cancerous. Many newer drugs are given by mouth, thus minimizing needles, travel, and timein the doctor’s office. Even older pharmaceuticals have been rendered safer by devising a more sophisticated dosing schedule: metronomic chemo refers to smaller doses given more frequently, just enough to keep the cancer from expanding without producing negative side effects.

Because of their innocent and enviable outlook on life, pets do not need to exhaust every avenue of treatment before they hang up their spurs. They don’t fear their eventual passing like humans do and don’t have a concept of tomorrow or next month. Ittherefore makes no sense for them to endure a lot of discomfort today as an investment in the future, and a veterinary oncologist would never ask that of them. Less than 5% of chemo patients ever become uncomfortable enough to warrant an overnight stay in the hospital, and approximately 80% suffer no unpleasant effects at all from the treatment.

Furthermore, there is always a convenient exit ramp for dog and cat chemo patients. Electing to embark on chemotherapy is not a binding commitment, and seeing an oncologist is only a fact-finding mission with no strings attached. So when the topic of pet chemotherapy comes up (and it will), don’t run the other way. It’s not a dirty word.

Dr. M.S. Regan