Dog Cancer Symptoms and Diagnosis

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Family around dying dog
Family Around Dying Dog

Any dog can contract cancer, but it mostly occurs in older dogs, partially because better nutrition and vet care mean dogs are living longer than in the past. Cancer strikes one in every three dogs according to the National Canine Cancer Foundation. For dogs over 10 years of age, approximately half of the deaths are cancer-related. As in humans, there are many types of cancers that affect dogs and many clinical signs that can be observed.

Cancer is an abnormal growth of cells that are localized in one part of your dog's body or that is aggressive and spreads throughout the body. The causes of cancers are largely unknown, making prevention difficult. Being aware of possible signs of cancer in pets helps provide early detection and care.

Breed Disposition to Cancer

Cancer is seen more often in some breeds than others, notably golden retrievers, boxers, Bernese mountain dogs, Great Danes, and greyhounds—primarily for bone cancer or osteosarcoma. Some lines may carry the genetic susceptibility to certain types of cancers. Researchers are studying both canine and human genomes to unlock the genetics of cancer.

Possible Signs of Cancer in Dogs

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.

short-coat white dog near white wall
short-coat white dog near white wall
black and white border collie
black and white border collie

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

  • Any new lump or bump
  • Sores that won't heal
  • A change in size, shape or consistency of an existing lump
  • A runny nose, especially if it is bloody
  • Difficulty urinating or bloody urine, which is also common with urinary tract infections
  • Straining to defecate, or thin ribbon-like stools
  • Vomiting or diarrhea, both of which are common with many other diseases
  • Limping or a change in your pet's regular gait
  • Foul breath, excessive drooling or teeth that have moved
  • Drainage and odor from the ears, which is also common with ear infections
  • Increased water intake and urination
  • Lethargy or lack of appetite
  • Weight loss
  • Difficulty swallowing or eating
  • Difficulty breathing

Cancer Treatment Options

Any time your pet's behavior changes, you should check in with your veterinarian. For cancer as well as other illnesses, early diagnosis and treatment are key to a favorable outcome. Treatment for cancer can involve surgery, chemotherapy, and radiation, but the best option is to catch it early before it spreads.

Not every cancer can be treated successfully. Some owners opt out of aggressive treatment and instead work with their vets to provide pain management.

Nurse preparing operation for an anaesthetized dog in animal hospital
Nurse Preparing Operation For An Anaesthetized Dog In Animal Hospital

Is Prevention Possible?

You can't prevent all cancers, but you can take steps to lower the chances your dog will develop it. Healthy nutrition and exercise help. So can having your dog spayed or neutered when it is young. This prevents most reproductive cancers. Your vet may prescribe specific vitamins for your dog.

Even though prevention of cancer isn't usually possible, when you find out about cancer early, your dog has the best chance for a successful outcome. Be vigilant and proactive to protect your pet.