All About Cancer.
Explore cancer types
Most common cancers in dogs
Canine Cancer Information
Understanding cancer
Cancer starts when cells begin to grow out of control. Learn the basics of how and why, in plain language.
Risk and prevention
Breed, age, genetics, and environmental exposures all play a role. Nothing guarantees prevention, but some things help.
Screening
Routine vet exams, bloodwork, and newer early-detection blood tests can catch disease before symptoms appear.
Diagnosis, tests & staging
What a biopsy, grade, and stage actually mean, and the questions worth asking at your next appointment.
Making treatment decisions
Surgery, chemotherapy, radiation, and newer immune-based therapies, benefits, limits, and what a course of care looks like.
Cancer care
Learn what a care plan can include, from treatment and symptom management to finding the right specialist for your dog.
After treatment
Find support for follow-up care, monitoring, and helping your dog enjoy life after active treatment.
Guides by cancer type
Learn the common signs, how each cancer is diagnosed, and the care options that may be available.
Mast cell tumors
skin
Mast cell tumors are common skin tumors that can look very different from one dog to another. A lump may be small, red, itchy, or change size. Testing and grading are important because behavior ranges from low-risk to aggressive.
Hemangiosarcoma
Blood vessels
Hemangiosarcoma is an aggressive cancer of blood-vessel cells. It commonly affects the spleen, heart, liver, or skin and may show few early signs. Sudden weakness, collapse, or a swollen abdomen needs urgent veterinary care.
Osteosarcoma
bone cancer
Osteosarcoma is the most common bone cancer in dogs. It usually begins in a limb and is seen most often in large and giant breeds. Ongoing limping, pain, or swelling deserves a prompt veterinary assessment.
Lymphoma
Immune system
Lymphoma is a cancer of lymphocytes, a type of immune-system cell. It can affect lymph nodes and internal organs. Swollen lymph nodes, tiredness, weight loss, or changes in appetite are common reasons families seek advice.
Soft tissue sarcoma
Connective tissue
Soft tissue sarcoma is a group of tumors that can arise from muscle, fat, nerves, and fibrous tissue. They may first appear as a slow-growing lump. The tumor grade helps the veterinary team understand how it may behave.
Bladder cancer
Urinary tract
Bladder cancer is most often urothelial carcinoma, which affects the urinary tract. Straining to urinate, frequent small urinations, or blood in the urine can resemble a urinary tract infection and should be checked by a vet.
Melanoma
Skin, mouth & toes
A cancer of pigment cells. Its behavior depends strongly on where it starts, especially in the mouth or on a toe.