Signs of cancer can progress slowly or rapidly. If your pet exhibits any abnormal behavior or function that is gradually getting worse instead of better, it should be examined by a veterinarian. Depending on the location of the tumor, your pet may feel fine and simply have a growing lump somewhere on the body, or the tumor may interfere with normal body functions.
Some warning signs may include abnormal growths or swelling, lameness, weight loss, loss of appetite, difficulty eating or swallowing, bleeding or discharge from any body part, exercise intolerance, and sores or wounds that do not heal. Difficulty breathing, inability to see, or difficulty urinating and defecating should be treated as an emergency.
Tumors are usually poorly innervated and are not painful in and of themselves. However, the tumor often will destroy the surrounding normal tissue, which can cause pressure or pain. Pain can result from damage to bones, soft tissues or directly to nerves.
It can be difficult to assess pain in animals. A sharp pain, such as stepping on a stone, might elicit a yelp, whine, cry or limp. However, chronic, aching pain can be much more difficult to pinpoint. Often animals that are in pain simply do not keep up regular habits. They may have a decreased appetite, lose interest in playing and going for walks, or begin to restrict their activity to certain parts of the house.
If your pet exhibits these signs or if a minor limp does not resolve with a few days of rest, your veterinarian should examine your pet. Some pain is managed by surgical removal of the tumor or treatments such as radiation, some by pain medications. You should not give your pet any over-the-counter or prescription pain medication without first consulting your veterinarian. Some medications used in people are toxic to animals. Tylenol (acetaminophen), for example, is fatally toxic to cats.