We have recently been informed by an American Heart Association committee that owning a pet decreases your cardiovascular risk. Since I am of the age when a coronary event is almost inevitable, the opinion of the committee caught my attention.
I am not much into pets, and I am not what you would call a dog lover; but I have had a dog that I really loved. Her name was Cassiopeia, "Cassie" for short, named after my then–10-year-old son’s favorite constellation. She was a warm and attentive golden retriever who jumped up on my car to greet me every evening when I came home from the hospital. My wife, who dutifully walked her every day, rarely got so much as a tail wag. She was clearly "my" dog and, like any person or animal that comes up to you at the end of the day with a lick or a kiss, was someone to be cherished.
In her 10th year, Cassie’s kidneys failed. After several weeks of daily administration of intravenous fluids, I gave up and took her to the vet to be euthanized. I freely admit that I was mildly depressed for a few weeks after she died. We never got another dog because my wife refused to continue to take care of an animal that never showed any appreciation.
The American Heart Association’s position on the benefit of pet ownership in the reduction of cardiovascular risk is one of at least three scientific statements that the organization makes each month. It did bring to mind the effect of Cassie on my psyche and the potentially beneficial effect that she had on my coronary arteries. However, I would have to admit I have failed to pay much attention to previous proclamations by well-meaning scientific bodies like the AHA committees. I have ignored the advice about my large coffee intake, my lack of daily exercise, and the amount of salt I put on my steak.
This particular statement by the AHA, however, was cautious about the justification of the canine-human interaction and indicated that there are scant randomized data to support the claim, and what existed related to cats, a species to which my wife is allergic. The recent dog–heart disease statement had come about as a result of a "growing number of news reports and medical studies" that purported to show a beneficial relationship between pet ownership and heart disease. It is amazing how one fails to notice a brouhaha right in our own midst. According to the New York Times account, the public uproar had reached such a "point that it would be reasonable to formally investigate" the issue.
But how would you ever try to design a trial testing the hypothesis that owning a dog was a panacea for cardiovascular disease? It is not clear what mechanism of action could be attributed to the presence of the dog. Was it exercise or depression? Of course, members of the committee jumped to the obvious relationship between exercising the dog and exercising the human. The particular species of dog certainly could have importance. Should it be a big friendly golden lab, a huge Great Dane, or a little Pekingese? Did its weight or disposition have any importance? How could you ever get rid of all of the variables? Forget the idea of a randomized trial; let’s just deal with the science of the matter.
I still could not forget Cassie and I tried to see how a new dog could help me. I thought about how my wife would take this, but I decided that her unhappiness would tip the balance against getting another dog. Another Cassie to bolster my psyche just doesn’t seem to be in the cards. In my own situation I wasn’t going to exercise the dog anyway. I had already assigned that responsibility to my wife, and I am not prepared to take that from her, even though she was willing to pass it on to someone else. I think that I will do without a dog and just try to carry on.
Dr. Goldstein, medical editor of Cardiology News, is professor of medicine at Wayne State University and division head emeritus of cardiovascular medicine at Henry Ford Hospital, both in Detroit. He is on data safety monitoring committees for the National Institutes of Health and several pharmaceutical companies.