Early Signs of Cancer in Dogs

Early signs of cancer in dogs will depend on the type of cancer. Types of cancers that affect dogs include breast cancer, leukemia, lymphoma, osteosarcoma (OSA), prostate cancer, testicular cancer, thyroid cancer, tonsillar cancer, and transitional cell carcinoma of the bladder. Cancer in dogs, no matter which type, may be treated with positive results if the condition is caught early enough. In some cases, symptoms may not appear until the later stages of the disease, while in others, the signs appear early enough to signal a problem.

Common Early Signs of Cancer in Dogs

Unfortunately, many of the symptoms listed in this section are also symptoms of other less serious conditions. However, any symptom should be a cause for concern so please follow-up with your veterinarian if you suspect that your pet might be ill. Some common early signs of cancer include:

  • Depression
  • Weight loss
  • Frequent urination
  • Lack of energy
  • Fever
  • Loss of appetite
  • Vomiting
  • Diarrhea
  • Constipation

Signs of cancer that may appear in the later stages of the disease include a distended abdomen, growths on the skin, testicles, or breasts and lumps underneath the skin.

Cancer Factors to Be Aware of

While the symptoms listed above could early signs of cancer, they could also be signs of a urinary tract or bladder infection, food poisoning, an upset stomach or other less serious condition. This is especially true if your pet is young or a breed that has a rare incidence of cancer. For example, osteosarcoma (OSA) occurs more frequently in large or giant breeds than in smaller breeds. In addition, the majority of cancers occur in middle-aged and older dogs. According to Debra M. Eldridge, DVM and James M. Giffin, MD, because companion animals are living longer and enjoying a higher quality of life, it is likely that cancer will be diagnosed with increased frequency.

Cancer Screening for Dogs

Most cancers  can be detected during a routine physical examination. This means, regular veterinary visits provide the opportunity to detect cancer at an early stage. This has important implications for the life and health of your dog. As a general rule of thumb, dogs ages seven and older should have a physical examination a minimum of once a year. If your dog’s health is questionable or if he is a member of a susceptible breed, a physical examination several times a year may be in order. If any signs develop, especially in geriatric dogs, he should be taken to a vet immediately.

Danger Signs in a Geriatric Dog

Older dogs are typically less energetic, so this symptom may go unnoticed. If your dog is less energetic, but his condition is accompanied by any of the sudden onset of any of following symptoms, please visit your vet immediately.

  • Loss of appetite and weight
  • Coughing or rapid, labored breathing
  • Weakness or exercise intolerance
  • Increased thirst and/or frequency of urination
  • Change in bowel function with constipation or diarrhea
  • Bloody or purulent discharge from a body opening
  • An increase in temperature, pulse or breathing rate
  • A growth or lump anywhere on the body