Osteosarcoma accounts for more than 85% of all bone tumors in dogs. It is the most common type of primary bone tumors that is highly malignant and metastatic. This type of tumor causes destruction to the bone and tends to spread to other organs.
Osteosarcoma in dogs can affect:
– appendicular skeleton (limbs)
– axial skeleton (skull, ribs, pelvis, spine)
Most canine osteosarcoma develops in the appendicular skeleton. Appendicular osteosarcoma is 2 times more likely to occur in the forelimbs than the hind limbs.
Tumor location on forelimbs: distal radius (adjacent to the carpal or wrist joint) and proximal humerus (adjacent to the shoulder joint)
Tumor location on hind limbs: distal femur (lower part of thigh bone) and proximal tibia (upper part of shin bone)
Breed, Age and Sex Predisposition
Osteosarcoma in dogs is common in large and giant breeds such as Scottish Deerhounds, Great Danes, German Shepherds, Labrador Retrievers, Rottweilers, Boxers and Saint Bernards. It affects both younger (aged 1-2-years) and older (aged 7 years onwards) dogs.
Small dogs are less likely to develop osteosarcoma, and even if they do, it is usually axial osteosarcoma.
Male dogs are more prone to developing osteosarcoma than female dogs.
Osteosarcoma in Dogs Symptoms
Canine osteosarcoma symptoms are determined by the location of tumor in appendicular and axial skeleton.
Symptoms of appendicular osteosarcoma or tumor in the limbs:
Symptoms of axial osteosarcoma (depend on the affected bone):
– eating difficulty
– breathing difficulty
– nasal discharge
Initially, osteosarcoma in dogs symptoms are subtle and intermittent. As the tumor grows and destroys the bone, lameness becomes persistent and can result in pathologic fracture. Swelling at the tumor site becomes obvious and the increasing pain can result in:
– loss of appetite
– weight loss
– reduced activity or reluctance to exercise
See the next post on: Canine Osteosarcoma: Treatment, Prognosis & Life Expectancy