As a veterinarian for many years, the toughest diagnosis that I have ever made is bone cancer. The main reason for this is because the client has brought her dog into my office for a lameness, expecting a quick resolution, only to find out that her dog has a malignancy that is going to kill him. I have literally seen caretakers collapse to the ground when told the news. There is no way to soften this unexpected blow; like being hit by a bus.
The first time I ever heard about bone cancer (osteosarcoma) was when I was in undergraduate school at Texas A&M. We were getting ready to play our rival in football (University of Texas) when we heard that their starting safety had been diagnosed with bone cancer. Most of us had never heard of the disease but it sounded awful. In a matter of days, he had had his leg amputated and we were all quite aware that his football days were over at the early age of 21years. Texas went on to win the game and the conference championship and played in the Cotton Bowl. In the time between the news and the bowl game, Freddy was dead.
Osteosarcoma affects dogs much more than cats, in particular large breed dogs. It appears that the larger the breed, the more predisposed that it is for osteosarcoma. This is likely due to the extremely high bone cell regulation and re-growth during normal bone life. No one knows why pets or people get bone cancer but I have treated many that had a previous injury to the affected leg. This is not the case for many.
The problem with bone cancer is that by the time the dog starts limping from the pain of the cancer, the highly malignant cancer has already spread to other parts of the body. This is why it is so deadly.
As I mentioned, the first symptom that we see in pets is limping. Usually, when the vet examines the dog, it is found that there is one particular spot on the bone of one leg that is painful. An xray is usually taken, which reveals the classical osteosarcoma appearance of a bone that is both over-growing and over-destroying itself. We call this a “star burst” appearance. A biopsy is needed to confirm the diagnosis, but if it is a large breed dog, it is likely an osteosarcoma. The other possibility of such a bone lesion is an infection in the bone, either bacterial or fungal. The biopsy will give the correct diagnosis.
Once the diagnosis is made, the first decision that has to be made by the caretaker is whether or not to have an amputation done. This can be difficult and many things need to be taken into consideration in making this decision. There is no absolute right or wrong. We start by asking ourselves why we should consider amputation.
We acknowledge that the cancer has likely spread and that amputation will not keep that from happening. The horse is already out of the corral. However, we need to address our specific problems clinically.
Bone cancer is one of the most painful diseases that we find in pets. So, we have two problems, pain and cancer. Most dogs with bone cancer end up being euthanized due to the pain than the spread of cancer, so pain control is adamant for any quality of life. Amputation will eliminate the pain problem for sure. But, it is not that black and white.
I had a couple with a Boxer that had been diagnosed with osteosarcoma come to my office for a second opinion and an alternative approach to the cancer. I remember watching them walk up the sidewalk toward my office, The poor dog could barely walk, he was in so much pain. The couple walked in front of him and tugged on his leash, encouraging him to follow them. He could not put any weight on the extremely painful leg.
I examined the dog and found the enlarged boney cancer in the humerus of the front leg. I talked to them about possible amputation but the couple was in conflict between the two as to what would be best. The wife wanted the operation and the husband did not. We tried to treat the pain but it was not successful. A couple of weeks later I told them that because the dog was in so much pain, I could no longer treat the dog unless the amputation was done.
They had the surgery done and returned to the office in a couple of weeks after the surgery. I watched them walk up the sidewalk again. This time, the dog was out front, happily pulling them towards the office. The relief from the painful leg removal was remarkable and it certainly improved his quality of life. He lived another 10 months with the cancer, but did so happily.
I personally had a dog with bone cancer and she was extremely painful and did not respond favorably to attempts at reducing the pain with meds and supplements. I did the amputation and she greatly improved and was running and playing with our other dog.
This is not to say that they amputation should always be done. Each dog should be evaluated individually and carefully look at everything before making the decision.
Chemotherapy should not be considered as osteosarcoma does not respond favorably to the drugs. To subject a dog with bone cancer to these drugs in my opinion reduces the quality of life during its remaining time. Some oncologists are doing radiation therapy to help reduce the pain and this is a consideration. I personally like to use alternative modalities like Chinese medicine for pets with bone cancer. In Chinese medicine, there are specific herbal formulas that reduce the cancer growth as well as relieving pain. Diet modification is usually needed as well.