According to the National Canine Cancer Foundation (USA), 1 out of every 3 dogs get cancer which is fatal in >50% of the cancer cases.
1. Lymphoma. Cancer of lymphocytes - the immune system cells. Swollen lymph nodes, skin lesions, mass in the abdomen. Usually detect by owner or groomer - lump around the neck, in front of the shoulder or behind the knee. Chemotherapy can extend life and make the dog feel better and eat.
2. Mast cell tumours. 20% of the skin lumps and bumps. May be localised or metastasize (spread throughout body). If not spread, surgical removal witho or without radiation is sufficient.
3. Osteosarcoma. Bone cancer. Long leg bones of large dogs. Amputation and chemotherapy. Signs - limping. Usually has spread when discovered.
4. Skin cancer. Melanoma and squamous cell carcinoma most common. If latter occurs in the mouth or toes, it is more aggressive.
5. Soft tissue sarcoma. Various cancers of the connective tissue. Locally aggressive. Recur as it sends tendrils of tumour cells. Surgery and radiation but recurrence is common. E.g. Haemangiosarcoma usually spreads from spleen. No symptoms till advanced. Spleen removal plus chemotherapy b ut less than one year of life.
6. Mammary cancer. Common in unspayed female dogs and those spayed after the first or second hea. 50% are malignant. Multiple glands. Early detection, simple surgery.
Diagnosed, graded and stage. Low, intermediate and high grade cancers.
Grade - how much cancer has spread.
Staging - Tests done - blood test, chest X-rays, abdominal ultrasound, CT scans.
Treatment - type and stage of cancer. Those that behave locally are treated with surgery and radiation. Systemic cancers or those that have spread - chemotherapy, including steroids or non-steroids and immunotherapy. Option not to treat - quality of life - palliative care focused on symptom pain relief rather than cure - lower radiation doses, pain killers, steroids, holistic care including acupuncture and herbal medicine.
Immunotherapy - e.g melanoma vaccine. Needs to wait.
Each dog is unique. Hard to predict.
Malignant cancers that can be completely removed - best chance
Aggressive systemic cancers like lyphoma, osteosarcoma and haemangiosarcoma - poorer prognosis.