Osteosarcoma or bone cancer is the most common cancer in dogs. It is important to first identify the primary symptoms and signs of Bone Cancer in dogs which is the first step to know that your dog may require medical attention from your local veterinarian. Diseases and symptoms do vary from dog to dog, so it is always best to consult your veterinarian as soon as any of the symptoms is witnessed.
Out of any animals, usually in dogs as well as any household pet, it is the upper or the lower long bones of the front legs that get affected. Sometimes the jaws and facial bones too get affected. Initial symptom is limpness and subsequent swelling in the bones and joints. Over time, the areas where the bone tumors are located will become swollen, hard and extremely painful.
Symptoms of bone cancer in dogs are lameness which is progressive and of varying severity, pain and swelling around the affected area of the leg; most often evident in one leg rather than several; broken bones called pathologic fractures at the tumor site, caused by bone weakness from the cancer; usually no history of physical injury to the area, Swollen upper jaw (maxilla); usually painful swollen lower jaw (mandible); pain when opening the mouth, frequent nasal discharge, Swelling and pain along the spine, swelling and pain around the ribs, difficulty eating or chewing (dysphagia), lack of appetite, Respiratory problems (difficulty breathing; dyspnea) typically caused by rapid spread [metastasis] of the cancer from bone to lung tissue which can also be caused by osteosarcoma of the ribs.
A dog’s height and weight add to the probability of developing bone cancer than its breed. Larger animals usually develop osteosarcoma in only one of their legs. Smaller dogs can develop osteosarcoma in their legs, but they are equally likely to have this form of bone cancer show up in other parts of their skeleton. The exact causes of osteosarcoma are not known. But factors like ionizing radiation, chemical carcinogens, foreign bodies like metal implants, like internal fixators, bullets, and bone transplants), and pre-existing skeletal anomalies like site of healed fractures sometimes leads to osteosarcoma. It has also been associated with chronic osteomyelitis and in fractures in which no internal repair was used. Bone Cancer In Dogs is also seen due to bone infarcts. In dogs, injected with plutonium during experimental studies, the occurrence has been found to be rampant. Genetic factors are also believed to induce the development of tumors. Dogs with OSA have been found to have aberrations of the p53 tumor suppressor gene.
Treatment for bone cancer and Osteosarcoma in dogs involves steps depending on the gravity of the disease. The first step is to take lateral and craniocaudal radiographic projections. Bone biopsy may be performed as an open incisional, closed needle or trephine biopsy. The advantage of open technique is that a large sample can be procured that makes histopathological diagnosis more accurate. Amputation of the affected limb is the standard local treatment for canine appendicular osteosarcoma. A surgery called limb sparing surgery is a procedure that replaces a diseased bone and reconstructs a functional limb by using a metal implant, a bone graft from another person (allograft), or a combination of bone graft and metal implant (prosthetic composite). Most dogs perform well with amputation but in cases like severe pre-existing neurological and orthopedic diseases, limb sparing is preferred over amputation.