Osteosarcoma

Description: Osteosarcoma is a common and aggressive cancerous bone tumor, usually found in larger dogs. As the tumor grows, it breaks down the bone and takes over the surrounding area. Tumorous bone is much more prone to breaking than a healthy bone.
Symptoms:Lameness, swelling, pain.
Diagnosis: Diagnosed via radiographs - it is often easy to visually notice where the bone has been eaten away, and biopsy if necessary.
Treatment: Because of this aggressive type of cancer, the affected area must be surgically amputated.
(See example claim.)

Breeds prone to Osteosarcoma include: