Ostesosarcoma is an aggressive bone cancer in dogs, although it only makes up about 5% of dog tumours. Although it is more “rare” it often requires amputation as well as chemotherapy for treatment.
Osteosarcomas often affect older and large-breed dogs. The breeds who are most at-risk for developing this type of cancer include Great Danes, Saint Bernards, Great Pyrenees, Newfoundlands, Bernese Mountain Dogs, and Irish Wolfhounds. Other big breeds like Rottweilers, Labradors, Golden Retrievers, Shepherds, Dobermans, and Weimaraners are also at an increased risk. It is not very likely to find a bone tumour in smaller breed dogs and seldom happens in cats. Dogs that weigh over 80 pounds have been proven to be at least 60 times more certain to develop an osteosarcoma than dogs who weigh less than 75 pounds.
While older dogs are more likely to develop bone cancer, there does seem to be an increased incidence in 1 to 2 year old dogs too. Although it is not known why, male dogs are also more likely to have an osteosarcoma.
The cause of this type of cancer is unknown, although there is speculation that some type of mutation occurs in the bones’ growth plates. Another theory is that the cancers develop at the location of shock. The increased cellular activity at the location of a fracture or trauma might result in the development of carcinogenic cells, thus resulting in a tumour.
The signs of osteosarcomas are usually localized to where the tumour is. Most bone tumours develop on the limbs of dogs below the elbow or close to the knee. The cancer often forms at or close to the expansion (growth) plates. Affected dogs will most likely have visible bone swelling. These tumours frequently produce discomfort in the joint that will first be spotted by the dog’s owner as lameness in the limb.
It is extremely important to seek out your vet if you notice any of these signs immediately. Your vet will need to do a biopsy to properly diagnose the problem as an osteosarcoma, rather than another type of bone infection that could be displaying the same symptoms. This goes for any type of dog tumours that you might feel or see on your beloved dog.