Cancer is the leading cause of natural death in older dogs and cats. Cancer accounts for almost 50 percent of pet deaths each year, but with the significant advances in detection and treatment of cancer in both humans and pets, cancer is no longer considered a “death sentence”. Approximately one in four dogs and one in five cats will get cancer in their lifetime. Certain breeds are more susceptible than others to getting cancers. Using the latest treatments, quality and duration of life can be extended. Just as in people, the earlier certain cancers are found, the more likely they can be treated and cured. Treatments administered nowadays such as, radiation and chemotherapy tend to be well-tolerated by pets. There are many new drugs available to help alleviate the side effects of chemotherapy.
Following are signs that can indicate cancer may be present:
- Swollen lymph nodes: Located throughout the body, they are easily located behind the jaw or the knee.
- An enlarging or changing lump: Any lump on a pet that is rapidly changing or growing should be biopsied.
- Abdominal distension: If the belly becomes quickly enlarged, this could suggest a tumor. A quick ultrasound can detect the problem.
- Lameness: Unexplained lameness (especially in large or giant breed dogs) is a very common sign of bone cancer. Radiographs of the affected area are useful for detecting cancer of the bone.
- Chronic Vomiting or Diarrhea: Unexplained vomiting or diarrhea should prompt further investigation. Tumors of the gastrointestinal tract can often cause chronic vomiting and/or diarrhea. Radiographs, ultrasound examinations and endoscopy are useful diagnostic tools when this occurs.
- Unexplained Bleeding: Bleeding from the mouth, nose, gums or blood in the urine or stool, that is not due to trauma should be examined. Although bleeding disorders do occur in pets, they usually are discovered at a younger age. If unexplained bleeding starts when a pet is old, a thorough search should be undertaken.
- Cough: A dry, non-productive cough in an older pet should prompt chest radiographs to be taken. This type of cough is the most common sign of lung cancer. Please remember there are many causes of cough in dogs and cats.
- Straining to Urinate: Straining to urinate and blood in the urine usually indicate a urinary tract infection, however, if the straining and bleeding do not resolve rapidly with antibiotics or are recurrent, cancer of the bladder may be the underlying cause. Cystoscopy or other techniques that allow a veterinarian to take a biopsy of the bladder are useful and sometimes necessary to establish a definitive diagnosis in these cases.
- Oral Odor: Oral tumors do occur in pets and can cause a pet to change its food preference (i.e. from hard to soft foods) or cause a pet to change the manner in which he/she chews their food. Many times a foul odor can be detected in pets with oral tumors. A thorough oral examination with radiographs or CT scan, requiring sedation, is often necessary to determine the underlying cause.
The prevalence of pet cancers is distressing for those of us who consider our dogs as family members. Yet there’s also good news: About 50 percent of cancers in dogs are curable with surgery, chemotherapy or radiation.
Another 25 percent of canine cancers are controllable, meaning treatment will help to extend life and improve quality of life.
In the final 25 percent of canine cancer patients, it is unreasonable to consider prolonging survival because of the advanced nature of the cancer. In these cases, veterinarians have many tools to provide palliative care, meaning we seek to relieve pain and provide other supportive therapies so the patient is comfortable until the end of life.