Ten signs of cancer in pets

Seattle Pets Examiner February 13, 2012

Dr. Luminita Sarbu of Veterinary Oncology Center knows how important early diagnosis can be for pets who have cancer. “Cancer is one of the most common geriatric diseases affecting both dogs and cats, although it can develop in pets of any age,” she stated. “Cancer accounts for death in 50% of dogs over 10 years of age and 32% of cats over 10 years of age. Interestingly, dogs get cancer at about the same rate as humans do and in some cases, the cancers have a similar behavior.”

Just like with humans, the cause of cancer is largely unknown. “Cancer can involve any part of the body or organs, from the skin to more interior locations, such as lungs, liver, spleen, intestines, kidneys, brain, etc. As a result, the symptoms that we have seen when cancer is growing can be variable,” Dr. Sarbu stated. “But as pet owners, we are in best position to notice abnormalities and act as early as possible. Just as in human medicine, early detection and treatments do make the difference!”

Mast cell tumor on the nose

   Mast cell tumor on the nose





Dr. Sarbu cautions pet owners to realize that the following list, while helpful in helping discover cancer, is not necessarily always indicative of cancer or a serious condition. “It is important to realize that there is not a single sign that is associated with cancer and without appropriate evaluations, your veterinarian will not be able to determine if your pet has cancer or a non-cancerous condition, as well as determine what the treatment and outcome may be,” Dr. Sarbu stated.

The following list entails some of the warning signs that your pet may have cancer:

1. Lumps and bumps. Not all lumps and bumps on your pet's skin will be cancerous, but there is no way to know for sure without getting them tested by your veterinarian. A needle aspirate or a biopsy is commonly used to obtain a diagnosis. It is important to act fast and have the bump evaluated – as tumors grow, they become more difficult to remove and they may get more chances to spread to other organs. A handout on how to check your dog for lumps and bumps and most common cancers that can be found this way is posted on the Veterinary Oncology Center website.

2. Sores that persist or grow. When treated appropriately, sores should heal and improve over a few weeks. Persistent sores could be an indication of cancer and should be evaluated with a biopsy.

3. Weight loss is commonly found in pets with cancer, but it is a very nonspecific sign and can be caused by many other non-cancerous conditions. In cancer patients, the weight loss can be caused by lack of appetite (anorexia) or changes in the metabolism (cancer cachexia). Cancer cachexia an important prognostic factor in humans and pets.

4. Decreased appetite. Dogs and cats do not stop eating without a reason. While poor appetite does not automatically indicate presence of cancer, it is something that needs to be discussed with your veterinarian. In cancer patients, a poor appetite can be caused by tumors in the mouth and discomfort or nausea triggered by many cancers, especially those occurring in the intestines.

5. Difficulty eating or swallowing; offensive odor from the mouth; drooling. While dental disease can cause any of these symptoms, so can masses in the mouth or throat. Your veterinarian can evaluate the mouth during a routine evaluation to some extent, but to examine the deeper throat area, brief sedation or anesthesia is needed. Discovering these masses early is imperative for being able to remove them and have a better outcome.

6. Persistent limping or stiffness. Any pet may injure his or her joints or muscles and have temporary pain. Older pets commonly have arthritis that can lead to chronic pain and chronic limping. However, if pain develops suddenly or persists/worsens, it could be an indication of something more serious. The affected area can be evaluate with radiographs. Sudden lameness is especially worrisome in large breed dogs, which are more likely to develop bone cancer.

7. Changes in bowel or bladder habits such as chronic vomiting, diarrhea, increased thirst, increased urinations, straining to defecate or urinate are a sign of problems, although not necessarily cancer. Chronic slow progression can remain unnoticed for a prolonged period of time, allowing the disease to progress. Low-grade lymphoma is a common cancer in middle-aged and older cats that has a slow progression and remains undiagnosed, often for many months. The symptoms can be very vague (very gradual weight loss, gradual decrease in activity, intermittent vomiting, soft feces, etc.) and are commonly misinterpreted by pet owners as signs of aging. Anal sac adenocarcinoma affects dogs, causing straining to defecate as the mass becomes enlarged in the rectal area. By the time symptoms are seen, the cancer is fairly advanced. However, requesting that your veterinarian perform a rectal examination every time your pet is seen may give you the opportunity to discover it early, while surgery can still be performed easily.

8. Respiratory problems such as a cough, hoarseness, heavy breathing, and respiratory distress can be caused by heart and lung disease as well as cancer. Many cancers spread (metastasize) to the lungs and cause these symptoms. Sometimes the cancer can cause production of the fluid around the lungs, leading to immediate respiratory distress. Heavy breathing and respiratory distress do warrant an emergency examination, regardless of their cause.

9. Unexplained bleeding or discharge from any body opening. Bleeding from the mouth, nose, ears or any other areas (without a trauma, such as a cut) may be caused by a tumor being present inside.

10. Distension of the abdomen. A mass in the abdomen can grow and cause the belly to feel fuller and look larger. This typically happens over a period of time and it is especially worrisome if your pet looks thin otherwise . However, if a tumor ruptures in the abdomen or compresses certain vessels, it can lead to fluid accumulation in the belly and acute distension. Other non-cancerous conditions (such as heart disease, inflammation, etc.) can cause similar symptoms.

By being aware of these common signs of cancer, you can advocate for your pet and arrange early veterinary interventions. For more information about Veterinary Oncology Center and Dr. Luminita Sarbu, visit their website