If your dog or cat has any of these early warning signs of cancer, you should take him or her to your veterinarian as soon as possible for a more complete examination. In addition, you should keep your pet away from environmental toxins like lawn fertilizers and surface and rug cleaners that have warning labels relative to children and pets. Many veterinarians see a link between environmental toxins and cancer.

1. Swollen lymph nodes

These glands are located throughout the body, but are most easily detected behind the jaw or behind the knee. When these lymph nodes are enlarged they can suggest a common form of cancer called lymphoma. A biopsy or cytology of these enlarged lymph nodes can aid in the diagnosis.

2. Enlarging or changing lump

Any lump on a pet that is rapidly growing or changing in texture or shape should have a biopsy. Lumps belong in biopsy jars, not on pets.

3. Abdominal distension

When the stomach or belly becomes rapidly enlarged, this may suggest a mass or tumor in the abdomen, or it may indicate some bleeding that is occurring in this area. A radiograph or an ultrasound of the abdomen can be very useful.

4. Chronic weight loss

When a pet is losing weight and you have not put your pet on a diet, you should have your pet checked. This sign is not diagnostic for cancer, but can indicate that something is wrong.

5. Chronic vomiting or diarrhea

Unexplained vomiting or diarrhea should prompt further investigation. Often tumors of the gastrointestinal tract can cause chronic vomiting and/or diarrhea. Radiographs, ultrasound examinations and endoscopy are useful diagnostic tools when this occurs.

6. 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 they chew their food. Many times a foul odor can be detected in pets with oral tumors. A thorough oral examination with radiographs or CT scan, necessitating sedation, is often necessary to determine the cause of the problem.

7. Unexplained bleeding

Although bleeding disorders do occur in pets, they usually are discovered while pets are young. If unexplained bleeding starts when a pet is old, a thorough search should be undertaken.

8. 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.

9. 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.

10. Straining to urinate

Straining to urinate and blood in the urine usually indicate a common urinary tract infection; if the straining and bleeding are not rapidly controlled 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.