Dogs sometimes come to the vet for a limp and leave with a diagnosis of
lung cancer. Cancer in the chest can activate the leg bones to grow new
tissue -- causing swelling and pain in the legs. A more typical symptom
of lung cancer is a cough, although about 25% of dogs have no symptoms
until cancer is detected on a chest X-ray. The leg changes -- called
hypertrophic osteopathy -- go away once the cancer is treated.
