Ask a Vet: Should I Euthanize a Happy Dog with Cancer?

I took Kelly, my 11 year-old Labrador/Staffordshire mix, to the vet as her belly seemed to be dropping and her spine was sticking out more....

Dr. Eric Barchas  |  Feb 14th 2012

I took Kelly, my 11 year-old Labrador/Staffordshire mix, to the vet as her belly seemed to be dropping and her spine was sticking out more. The vet did an ultrasound and said he could see several spots on her spleen and liver, which indicated tumors. He suggested putting her to sleep earlier rather than later, as it is only a matter of time before one of the tumors could burst.

I am not sure what to do. Kelly still has a huge appetite and is wagging her tail. She also enjoys going for walks and swims, though she doesn’t last as long as she used to. Her legs seem a little weak. Should I take her to get a more thorough diagnosis (not just an ultrasound)? Many of her symptoms seem to point to Cushing’s disease, but I guess I am just being hopeful and there is no reason the vet would say she has cancer if he wasn’t sure.

If I do just accept that she has incurable cancer, I don’t know how long to wait. I don’t want her to be uncomfortable or get to the point where a tumour bursts, but I find it extremely difficult to think about putting her to sleep when she still seems fairly happy and energetic.

I’d greatly appreciate your advice.

Brisbane, Australia

Unfortunately, based upon your description I agree that cancer is the most likely diagnosis. However, if Kelly is happy I can’t sign off on putting her to sleep sooner rather than later.

You are correct that a sagging abdomen and prominent spine are commonly encountered in Cushing’s disease (a disease of the endocrine system in which blood cortisol levels are excessive). However, many other syndromes can cause the changes you describe. Cushing’s Disease usually leads to enlarged adrenal glands that are visible on ultrasound exams, and it sounds like your vet did not see these, although a vet must be an experienced ultrasonographer to consistently assess adrenal gland size.

If your vet found multiple similar focal irregularities in both the liver and the spleen, I am very worried that his diagnosis of cancer is correct. That said, an ultrasound alone is almost never enough to fully diagnose any condition. Basic blood tests and chest X-rays are a good idea if you have the resources to pursue further diagnostics. A repeat ultrasound with a specialist in radiology or internal medicine may yield more insight as well.

If the diagnosis, as feared, turns out to be cancer, then Kelly most likely will succumb to the condition at some point. Although the choice is yours and I would respect any decision you make, I do not agree that she must be euthanized any sooner than necessary.

Although Kelly may well have advanced terminal illness, it sounds like she is still enjoying her life. And, crucially, she does not have to live with one of the very difficult parts of a cancer diagnosis: knowing she’s sick. People with terminal illnesses often suffer depression because they know what the future holds. Kelly has no such issue — knowledge of the future no doubt is making you sad, but not her.

If she’s happy, why not treat each day as a gift and enjoy her remaining time with her?

If the diagnosis of cancer is correct, then one of the tumors may burst. Such ruptures usually lead to sudden internal bleeding, which causes weakness (due to low blood pressure and anemia) and sometimes difficulty breathing. When such a crisis occurs, it probably will be time to consider euthanasia. But if you act fast when this happens, Kelly will not suffer for long, and she probably won’t suffer very much at all. In my opinion, it does not make sense to euthanize her before she feels sick.