How is it possible that our dog is acting fine — no signs of disease — and have cancer?
This is a pretty common question. It’s also a common scenario. MANY dog lovers have gone to the vet to have a lump checked out, something that doesn’t seem to bother their dog. And then, sometimes even on the same day, the news arrives: cancer.
Whether this is a mast cell tumor, osteosarcoma, lymphosarcoma or some other kind of cancer, the news is horrific. There is not much that can truly prepare someone for the shock.
Blam: your dog is acting fine … but has cancer.
In their shock, many clients and readers ask: how did this happen?
My Dog Is Acting Fine. How On Earth Could He Be Sick?
It is very natural that this question arises.
If my veterinarian is saying that my dog has cancer, how did this happen?
Aren’t cancer patients sick?
Shouldn’t there be some other sign if it really is as bad as the vet is saying?
The answer is no, not necessarily. The key, in part, is in looking back to the natural world.
It’s In Their Nature
Here’s why: in nature, it is not helpful for animals to act sick.
Sick animals get eaten because they stand out from the pack. Sick animals attract the attention of predators.
Another reason acting sick in the wild is detrimental is that a dog could lose its pack position. To maintain their status among peers, it is better to be healthy and vigorous. Those acting sick lose status. Thus they have a strong social penalty for acting ill.
It becomes clear that showing signs of sickness can make matters worse for a dog in the wild. There is a strong instinctive drive hide illness.
Get a copy of the Dog Cancer Survival Guide to read more on canine cancer
What Works In Nature Doesn’t Work in Domesticity
This instinct creates a problem when our canine companions are in need of medical attention. Driven by this strong natural tendency, dogs hide their physical problems from those responsible for them: us!
Many medical problems (not just cancer) are kept under wraps, masked from caring dog guardians.
… Or Maybe There Are No Symptoms Yet
There is another reason dogs can act as if nothing is wrong while there is a cancer brewing. Maybe a dog has a malignant tumor, but it has not spread enough to cause really significant tissue injury.
You may know a human who found a lump, and it turned out to be cancer, even though they were otherwise healthy. They didn’t know the lump was malignant, because it didn’t cause pain.
Tissue injury is what causes pain, and some tumors just don’t cause enough injury as they brew and progress. Until they do, both humans and dogs with cancer can act normally.
Decompensation = Problems Become Clear
Cancer usually starts as just a few old, deranged cells piling up. They should have already been replaced by healthy, vital cells by a process called apoptosis. But cancer suppresses apoptosis (it’s one of the hallmarks of all cancers). No apoptosis = cells live forever.
No apoptosis = cells live forever.
If there is an apoptosis deficiency in the body, these cells will accumulate.
Meanwhile, the normal healthy cells continue to support your dog’s body, and your dog is acting fine.
This continues until those healthy cells can’t keep up.
Once the effect of the pile of deranged cells tips the scale, we see the problem.
This tipping point is called decompensation, a fundamental phenomenon in health and disease.
There is an in-depth discussion of cancer development in several chapters in my book. You may also be interested in reading chapter 3, for free, here.
Best to all,
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.