10 Common Signs of Cancer in Your Dog or Cat

10 Common Signs of Cancer in Your Dog or Cat

From that very first introduction to the way that they always seem to make a bad mood better, pets bring a certain kind of joy to the lives of pet owners that cannot be easily described. Their presence has been scientifically shown to boost the brain’s “happy hormones” and they are wonderful protectors, nurturers, and companions.

Because of the attachment that we have to our pets, cancer is a topic that pet owners rarely want to discuss. It is, however, an important topic that needs to be addressed. Realizing that something may be “off” in your dog or cat is incredibly emotionally jarring. Fortunately, science and technology have come a long way and a cancer diagnosis does not guarantee that your pet is in grave danger. In order to give your pet the best chance at recovery, it is important that you are aware of the top signs of cancer in your dog or cat.


Lumps or bumps do not automatically point to signs of cancer in your dog or signs of cancer in your cat, but they are not things that are worth putting off for too long. If the lump or bump does not resolve itself quickly, it is time to head to your veterinarian for a biopsy.

Bad Odor

If your dog or cat is emitting an unpleasant odor, there is a chance that the odor is being caused by cancer of the mouth, the nose, or the anus.

Abnormal Discharge

All abnormal substances fall into this category. For example, if you find blood in your pet’s stool, if your pet is vomiting or producing diarrhea, it’s time to take your dog or cat in. There are many benign causes for these issues, but they could be signs of cancer in your cat or signs of cancer in your dog. Further, if you find that your pet’s stomach is distended, that could indicate an overabundance of fluid inside of your pet’s body.

Wounds That Don’t Heal

Pets are going to get scratched up from time to time. If you notice that your pet has a wound that will not heal, it could be due to a malignancy.

Weight Loss

One of the most commonly known signs to watch out for is sudden weight loss in your pet that is not purposeful (such as a weight-loss diet).

Lack of/Change in Appetite

A lack of or a change in appetite is worrisome because dogs and cats are, first and foremost, animals. They are programmed to seek out food. If you find that your dog or cat is unable to eat or is disinterested in food, this could be a sign of cancer, like an oral tumor.


You know your pet well. If you pet has always been lazy by nature and has always passed his or her check-ups, laziness is not a grave cause of concern. However, if you begin to notice that your pet’s personality has changed and that he or she does not have the energy to go on walks or play like he or she used to, lethargy is worth nothing to your veterinarian.

Difficulty Breathing or Coughing

An array of diseases can be associated with your pet’s inability to breathe correctly. It does not always mean that your pet has cancer, but there is a small chance that your dog or cat’s breathing problems are due to cancer that has metastasized to the lungs.

Changes in Urination or Defecation

If your pet has blood or urine in its stool, has difficulty going to the bathroom, or goes to the bathroom too frequently, this could be a potential sign of cancer.


A limp, for example, is likely due to arthritis or a joint issue. With that being said, it could be a sign of bone cancer and is worth getting checked out.

It is important to remember that just because these signs could indicate cancer, it does not mean that your pet has cancer. Being proactive is one of the best things that pet owners can do for their pets. While dogs and cats cannot speak to us directly, they do provide an array of signs to let us know that something is wrong. It is our job as pet owners to listen to and pay attention to these signs in order to provide our pets with the same love and devotion that they provide us on a daily basis.

To learn more about the team at Central Texas Animal Hospital, view our team page or contact us today to schedule an appointment! We offer veterinary services for cats and dogs in the Pflugerville/Austin-Round Rock, TX area.