Signs of Cancer in Dogs

Facts about canine cancer and signs to be aware of

Large neck lipoma prepped for surgical removal © Janet Tobiassen Crosby DVM
Large neck lipoma prepped for surgical removal. © Janet Tobiassen Crosby DVM

Cancer is an unfortunately common disease of dogs - 1 in 4 dogs will die of cancer according to the Morris Animal Foundation. For dogs over 10 years of age, approximately 50% of deaths are cancer-related. Like humans, there are many types of cancers and many clinical signs seen.

Cancer is an abnormal growth of cells and may be benign (slow-growing, removable) or malignant (aggressive, spreading throughout body).

The causes of these cancers are largely unknown, making prevention difficult. Being aware of possible signs of cancer in pets will help provide early detection and care.

Breed Disposition to Cancer

Cancer is seen more often in some breeds, notably the Golden Retriever, Boxer, Bernese Mountain dogs, and Greyhounds (primarily for bone cancer, or osteosarcoma). Some lines may carry genetic susceptibility to certain types of cancers. Researchers are studying both canine and human genomes to unlock the genetic of cancer.


Possible Signs of Cancer

Cancer can affect any area of the body and any body system. Cancers of the skin, lymph nodes, gastrointestinal tract, blood and bone are common in dogs.

Here are some possible signs of cancer that warrant a visit to your veterinarian:

  • Any new lump or bump.
  • A change in size, shape, or consistency of an existing lump.
  • Runny nose, especially if bloody.
  • Difficulty urinating, bloody urine (also very common with urinary tract infections).
  • Straining to defecate, thin, ribbon-like stools.
  • Vomiting, diarrhea (common with many diseases).
  • Limping, change in gait.
  • Foul breath, excessive drooling, teeth that have "moved."
  • Drainage and odor from ears (also very common with ear infections).
  • Increased water intake and urination.
  • Lethargy, inappetence.

    Any time your pet is not "himself or herself" is time to check in with your veterinarian. For cancer as well as other causes of illness, early diagnosis and treatment are key to a favorable prognosis.

    Please note: this article has been provided for informational purposes only. If your pet is showing any signs of illness, please consult a veterinarian as quickly as possible.