January 05, 2011
Can anything be done to prevent the development of cancer?
This eight-month-old Lab's tibia shows a spiral fracture caused by a jump gone bad.
Q (Question) I would greatly appreciate your opinion and input regarding canine cancer. When I lost Ginger, my 9-year-old Brittany, to liver cancer, I began researching this terrible disease. At first I thought the New Jersey environment was to blame, but I found that canine cancer was widespread throughout the United States.
I heard suggestions of it being from the food, water, air and even the immunization shots. But I feed my dog the best food and give her natural spring water. After Ginger, I purchased a female German shorthaired pointer and lost her 11 years later to bone cancer. I get all my dogs spayed at five to six months of age.
Does the American Veterinary Association have any suggestions on what dog owners can do to reduce the risk of cancer to their best friends? All dog owners would greatly appreciate any suggestions you can offer us. I presently have Molly, a female GSP, and would do anything to help protect her from this terrible disease. --LC
A (Answer) I think we have to look at cancer in the dog just as we do cancer in people. I agree that it is a prolonged, painful process in many cases and the more we can do to spare our dogs that fate, the better off we all will be.
One thing I found out many years ago was that if in the course of an office visit examination I mentioned to the owner that the process we were noting in their dog could be cancer, their minds would close down, and I would be unable to communicate any more information to them on that visit.
Only after one or more additional visits, some corroborating lab work and time to reflect on the issue at home would owners come to the realization that their best friend did, in fact, have cancer. This process is very much like the process owners go through when faced with making a decision on euthanizing a pet.
While cancer does work in a similar way in both humans and animals, there are some differences. Dogs, for the most part, do not contribute to their problems by making poor choices. I said many years ago that I could not be a human physician because I would have no compassion for those people who came in with respiratory problems and smoked like a chimney.
Thankfully, not many dogs smoke, but they do suffer from the side effects of secondary smoke--probably not as much as people do, but they are still exposed. I feel that the most significant effect of tobacco smoke on dogs is that it inflames the mucous membranes in the back of the nose where the olfactory nerve endings pick up scent.
I admonish clients who smoke to not do it in an enclosed area (like the inside of a vehicle) where the dog has to breathe in that contaminated air. After all, they are on their way to an event wherein they expect their dog to use its nose to the maximum.
I feel that many chemicals and chemical compounds are especially dangerous carcinogens. Over time, we have found out that things like lead and mercury are not as safe as once thought. I can remember when 2,4-Dichlorophenoxyacetic acid (2,4 D) first came out and the manufacturer told us that it was so safe that you could drink the stuff. But DDT is gone because of its toxic properties. If someone tells me a chemical is safe, I just say to them, "Oh, pasture pie!"
You mentioned that you always give your dog bottled water to drink. I have a real problem with that one. Those products have no quality control or testing for contaminants. Besides that, have you ever considered that the process of making the bottles probably puts enough contaminants in the air to more than offset anything in your tap water? I do buy a bottle of water every now and then, but then I refill it with tap water from home and carry it around so I can look cool like everybody else.
I feel strongly that excessive challenge to the immune system leads to many problems in the body, and cancer may very well be one of those issues. I do know that golden retrievers have a high incidence of lymphoma and lymph-system-related diseases.
I do not know if these diseases are related to vaccinations or not, but goldens certainly seem to have a genetic predisposition to lymphoma. Boxers seem to have a higher incidence of cancer. Some breeds seem to have a higher incidence of mast cell tumors.
The sex hormones set up their target organs for tumors. Estrogen, progesterone and testosterone can influence the development of mammary tumors and prostate and testicular tumors. Spaying/neutering is obviously the way to counter this potential problem.
I think the bottom line is that we really have little control over the hidden carcinogens that our dogs may face. I think the best thing an owner can do is watch an aging dog closely and try to detect cancer development in its earliest stage. Do this by annual physical exam and, as the dog reaches middle age, include blood and urine analysis as an aid in early detection.
As I seem to be editorializing more so than usual this time, I will continue with one of my pet peeves. That is throwing Frisbees for a dog. That is not how the fracture occurred in the dog that the radiograph on the right was taken of, but it is the type I would expect to see happen when that activity is engaged in.
This radiograph is from an eight-month-old Lab actively in training for field trials. It shows a spiral fracture of the midshaft of the tibia, commonly called a "green stick fracture." It gets its name from its resemblance to the break that occurs when you twist a green stick.
This fracture occurred when the owner/handler attempted to keep a bumper away from the dog by holding the bumper up in the air above his head. The dog jumped after the bumper--similar to the videos we have all seen of dogs jumping after Frisbees--landed wrong and fractured his tibia. Obviously, the owner did not anticipate this happening.
Just as with cancer-causing agents, we cannot eliminate all risks of fractures in dogs. Certainly most fractures are the result of vehicle encounters and can be reduced in incidence by controlling one's dog. Dogs riding loose in the open box of a pickup are an open invitation for fractures.
I can still remember a client coming to pick up his dog from which I had surgically repaired a femur fracture. It had jumped out the back of the pickup when the truck was going down the road. And guess what? He picked the dog up and loaded it back into the box of the pickup.
, we often do not realize what we are teaching or doing with our dogs on a daily basis. I'm sure the owner of this young Lab now wishes he had taught the dog to sit and be rewarded with a tossed bumper, rather than unwittingly teaching him to jump up and try to grab it out of his hand.
Think about the times when your dog has returned with game, released it to you and then you began the game of trying to get the bird in the bag before the dog could grab it.
Have great hunting this fall and, by all means, keep your dog's safety in mind at all times.
Questions may be sent to me at firstname.lastname@example.org