The 10 Warning Signs
By Dr. Gerald S. Post
Pets have become members of our families and we want to insure
that they live the longest and best lives they possibly can.
As we have taken better care or ours dogs and cats they are
indeed living longer; yet despite this, or perhaps because
of this, cancer is one of the leading causes of death in pet
dogs and cats. Some estimates suggest that greater than 50%
of dogs over 10 years old will die of cancer. As a veterinary
oncologist, I would like to give pet owners some advice on
what things to look for in order to detect cancer in their
pets. The earlier you detect cancer the better your chance
of effective treatment. Below are 10 warning signs of cancer
in both dogs and cats. Please understand that these are just
potential warning signs and should not panic you, but prompt
a visit to your veterinarian.
1. Swollen lymph nodes: These “glands” are
located all 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. An 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. Many cancer patients
have weight loss.
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. Unexplained bleeding: Bleeding from the mouth, nose,
penis, vagina or gums that is not due to trauma should be
examined. 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
7. 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.
8. 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
9. 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.
10. 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 it chews
its 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.
Dr. Gerald S. Post is a Board-certified specialist in veterinary
oncology and the Founder and President of the Animal Cancer
Reprinted with the permission of Animal