The Pain of Osteosarcoma
I had a heart-breaking euthanasia appointment a few weeks ago. Euthanasias are always difficult, but usually I can focus on the relief/prevention of suffering aspect and feel pretty good about it when all is said and done. My overwhelming emotion on this evening, however, was simply, "this is just not fair."
My patient was an absolutely lovely (both physically and personality-wise) middle-aged greyhound. She had been diagnosed with osteosarcoma, a type of bone cancer, in a hind leg a few months previous and had undergone an amputation and chemotherapy, handling everything quite well until she started favoring another leg. Unfortunately, she had developed osteosarcoma in that limb as well, which is a pretty rare occurrence.
Her owners were incredibly dedicated to her and elected to proceed with radiation therapy to provide her with pain relief and hopefully a few more months of quality time. Unfortunately, this was not to be. On the evening after her first radiation treatment, one of the other family dogs accidentally knocked her over and she suffered a pathologic fracture of the affected leg, necessitating euthanasia.
Colorado is home to a lot of big dogs, and because of that, we see a lot of osteosarcoma. The disease is most commonly diagnosed in large and giant breeds like Saint Bernards, Rottweilers, Great Danes, Golden Retrievers, Irish Setters, Doberman Pinschers, and Labrador Retrievers.
I hate diagnosing osteosarcoma. A typical scenario goes something like this: An owner notices their dog limping a little bit. Thinking the problem is something relatively benign, like a touch of arthritis or a strained tendon/ligament, the owner makes an appointment with their veterinarian. The X-rays tell a completely different story, however, and the owner leaves the clinic having to face the fact that their dog has a fatal disease.
To make matters worse, osteosarcoma is one of the most painful diseases that we deal with in veterinary medicine. For owners who are unable or unwilling to pursue aggressive treatment (usually amputation or limb-sparing surgery followed by chemotherapy), pain relievers can often keep a pet comfortable for only a short period of time before even the most stoic dog is begging for mercy. For this reason, veterinarians will sometimes recommend amputation as a pain-relieving strategy. Osteosarcoma rapidly metastasizes (usually to the lungs, liver, or kidneys), so amputation without follow-up chemotherapy will not extend a dog’s life, but it may be the only effective way of dealing with the pain, letting the dog enjoy the time he does have left.
I hope I haven’t made you all paranoid and depressed. A lot of older, large breed dogs do develop a limp for relatively inconsequential reasons, but osteosarcoma should be on your radar screen, if for no other reason than to avoid being blindsided by a totally unanticipated diagnosis.
Dr. Jennifer Coates