The National Cancer Institute’s Center for Cancer Research reports around six million dogs in the U.S. are diagnosed with spontaneous cancer every year. While better understanding of canine nutrition and advanced veterinary technology is prolonging the average dog’s lifespan, the risk of developing cancer increases as dogs age. Recent reports indicate about half of dogs over 10 years old are diagnosed with some type of cancer.1 We must take it upon ourselves as concerned pet parents to know the warning signs of canine cancer.
Dogs get cancer at around the same rate humans do, but the disease tends to progress faster for our canine friends. The key to fighting it has always been early detection. Without the ability to voice their feelings, dogs often go undiagnosed. Sometimes their disease shows no symptoms until it’s too late for medical intervention to help. In many cases, however, an observant owner can save their dog’s life.
Regardless of your dog’s age, breed, or perceived health, it’s important to know about these common signs of cancer.
#1 – Unidentifiable Lumps
One of the easiest cancer symptoms to recognize is the presence of a tumor growing beneath the skin. Sometimes lumps are benign cysts, but an unusual growth always warrants a trip to the veterinarian. The lump needs to be removed and tested for the presence of cancer.
Just as there are several different kinds of cancer, there are several kinds of cancerous tumors. Mast cell tumors grow quickly and tend to itch and look inflamed. Snub-nosed dog breeds like Boxers and French Bulldogs develop this type of tumor more than other breeds. Other types of tumors include histiocytoma tumors that are typically small and hairless, and tumors related to lymphoma are characterized by lymph node swelling under the jaw and behind the knees.6
Veterinarians encourage dog owners to inspect their pets’ skin at least once a month. Tumors can be large, but a small lump the size of a breath mint can be equally as dangerous.
#2 – Sudden Weight Loss
As long as the dog isn’t on a strict diet, their weight should remain relatively steady. Noticing weight loss is easiest in small dogs that are picked up often and dogs with short hair. A good way to quickly judge a dog’s weight is to look at them from above to see if their waistline looks more defined than it used to be. You can also palpate their sides regularly to feel how close their ribs are to their skin.
It’s harder to judge weight loss in big dogs with lots of fur. A 70-pound rough Collie with progressing cancer could be losing weight, but their fur and the lack of a convenient scale could mean the symptom goes unnoticed. For these dogs, it’s important to either bring them to the vet regularly for check ups or devise a method of checking their weight at home.
#3 – Lack of Appetite
Sometimes dogs push away their dinner when they have an upset stomach, and they’re usually back to eating within a day. Dogs that don’t act hungry for more than two days at a time, however, could be dealing with something more serious.
A tumor pressing against the intestines is a common reason why dogs stop eating. Food going through a cramped intestine is uncomfortable, and the dog quickly decides not eating is the way to make themselves feel better.5 If it’s cancer, regaining appetite is essential for recovery. Cancer will drain the body’s energy and make it harder for the immune system to fight back. Nutrients derived from food will be essential to keep up the dog’s strength.