Cancer is a terrifying prospect as cells divide uncontrollably and our canine companions are not immune to this. One of the most terrifying prospects of cancer in our canine companions is osteosarcoma. Osteosarcoma is the most common bone tumor in dogs accounting for 85% of all canine bone tumors. Osteosarcoma is a type of cancer which results from the rapid, uncontrolled division of cells. This form of cancer is highly aggressive and can metastasize and spread to other parts of the body very quickly, especially the lungs and other organs. Thus, it is important to understand the risk factors as well as the symptoms in our canine companions. Dogs that are at a high risk for developing osteosarcoma are large breeds of dogs, male dogs, as well as dogs that have received trauma to the bone. This is due to the fact that the during periods of rapid growth, which is seen very evidently in large breeds that grow in size very quickly, or periods of bone repair after trauma where the cells are dividing rapidly for repair there is a higher risk for mutations and osteosarcoma can develop. It is essential as a pet owner that one is able to recognize possible symptoms of osteosarcoma in order to try and treat it as soon as possible in an attempt to improve the prognosis for our beloved pets. The early symptoms may seem very subtle such as swelling, joint or bone pain when the area is touched, or lameness which can occur suddenly due to intense exercise or progress slowly over time. As osteosarcoma progresses, dogs can experience a loss of appetite and lethargy and a visible mass can occur. The location these tumors are most commonly found is on the wrists of the front limbs of dogs, but it can also be seen in other parts of the front legs as well as the hind legs or other locations of bone. These tumors tend to not be located near elbows or knees, but there are always exceptions, so make sure to see your local veterinarian!
Once you are at the veterinarian there are several ways to diagnose an osteosarcoma. The most common ways are through histopathology and radiographs. Radiographs or x-rays are taken in order to take an image of the mass and surrounding area. The diagnosis for osteosarcoma is most often confirmed by radiographs alone since the image of the area tends to show a “moth-eaten” appearance. A histopathology can also be done and this takes a sample of cells via a fine-needle aspirate or a bone biopsy to confirm that it is indeed osteosarcoma. Osteosarcoma can be categorized as stage I which is low-grade tumors without evidence of metastasis, stage II high- grade tumors without metastasis, or stage III metastasis has occurred.
Once a diagnosis is confirmed the prognosis unfortunately tends to be poor, but there are several actions that can be taken for our canine companions. Amputation of the affected area is often an option and used in conjunction with chemotherapy since this will inhibit metastasis of cells and prevent the cancer from spreading. But due to rapid nature of this disease the most common treatment is to try and make our pets as comfortable as possible with painkillers and other comfort care. Osteosarcoma is an unfortunate affliction for our canine companions, but knowing the signs and options lets us be proactive to try and catch it early so man's best friend have the best prognosis possible!
