Malignant tumors of bones in a dog
Last reviewed: 19.10.2021
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Tumors of bones can be malignant or benign. Osteosarcoma and chondrosarcoma are the two most malignant tumors of bones. Osteomas and osteochondrosis are benign.
Osteosarcoma is the most malignant type of bone cancer in dogs. It affects dogs of any age, the average age of dogs with osteosarcoma is 8 years. This type of cancer affects with the same frequency dogs of male and female. Large breeds, such as St. Bernards, Newfoundlands, Great Danes and Pyrenean Mountain Dogs, have a 60-fold greater chance of developing osteosarcoma than dogs weighing less than 10kg. In large dogs, such as the Irish setter and boxer, the probability of developing osteosarcoma is 8 times higher. Small dogs, this cancer is infrequent.
Osteosarcoma most often occurs in the forepaws, then the hind legs, flat rib bones and lower jaw are followed by the frequency of development. Most often, the first sign is lameness in a mature dog, which had no injuries. Usually, this is almost not paid attention, until there is swelling of the limb. Pressing on the tumor causes pain. In the place of the tumor, fractures can occur.
The results of an X-ray examination may give grounds for suspecting the disease, but the exact diagnosis depends on the biopsy of the tumor. Osteosarcoma is an aggressive cancer that spreads quickly to the tumor.
Chondrosarcoma is on the second place among malignant tumors of bones in dogs. The median age at onset of the disease is 6 years. This tumor often affects the ribs, bones of the nose and pelvis. It is a large dense, painless edema in a place where there is cartilage. This tumor also metastasizes into the lungs, but not as aggressively as osteosarcoma.
Treatment: Malignant tumors, such as osteosarcoma and chondrosarcoma, must be treated aggressively. Because these tumors give metastases to the lungs, it is very important to perform a chest x-ray before surgical treatment. The dog should undergo a complete physical examination, including a detailed blood test and a fine needle aspiration biopsy of any enlarged lymph nodes.
The only effective way to treat osteosarcoma of the limb is partial or complete amputation. Most dogs can do well on three legs. Although amputation rarely heals cancer, it alleviates the pain and improves the quality of the dog's life. It should be carried out at least one joint above the affected bone. In some veterinary centers, new surgical techniques are practiced that allow the limb to be preserved.
Chemotherapy in addition to amputation increases the life span of dogs affected by osteosarcoma, but does not increase the rate of treatment effectiveness. If the cancer has already metastasized or is at an advanced stage, the possibility of radiation therapy may be considered, but this also does not provide a cure. The osteosarcoma of the lower jaw is treated with radiotherapy, to which it has moderate sensitivity. Radiation is also used to relieve pain.
Complete surgical removal of chondrosarcoma gives relief, but it is not worth treating it as healing.
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