In a way, I do. But it’s probably not the way that you’re talking about.
In developed countries, diseases such as thyroid conditions, kidney failure, cancer and heart failure are becoming more common among pets. There is rampant speculation about what causes many of these syndromes. Breeding, chemical body burden, and yes, diet probably play a role. But there is one factor that is not in dispute. All of the problems listed above occur most often in older animals.
Another thing that is not in dispute: on average, animals in developed countries are living longer than in the past. There is no doubt that the increased life expectancy that animals now enjoy is playing a role in the increased prevalence of cancer, hyper(and hypo)thyroidism, heart failure and kidney failure.
I am not saying that increased life expectancy is the only factor involved in this phenomenon. But it definitely is a factor.
Now, consider developing countries. In recent years, I have observed dogs and cats in Nicaragua, Mongolia, Laos, El Salvador and Botswana (among others). The diseases that are so common in the US, New Zealand, and other developed countries are basically unheard of in developing nations. The explanation is simple. Animals in developing countries don’t live long enough to develop these problems.
Animals in developed countries live longer, on average, for a number of reasons. Cats are more likely to be kept indoors. Pets are more likely to be spayed or neutered. They are more likely to receive vaccines. They are more likely to receive basic medical care and be treated for parasites. And they are more likely to be fed pet food.
I am not saying that the pet foods on the market now are perfect. History may reveal tremendous problems with them. There is always room for improvement. We may discover in the future that certain ingredients in pet foods promote some of the diseases mentioned in this post.
However, there is no doubt that the currently available pet foods represent a massive improvement over the diets that animals receive in developing countries–table scraps, garbage and prey animals.
The widespread use of pet food has contributed to increased life expectancies for pets. So yes, in that sense pet foods are contributing to the increase in health problems that we are seeing in the developed world.
For those of you who want my opinion on which food is the best: I weighed in on that matter a while back. Click here to see what I had to say.
For more information on dogs in developing countries, I recommend the book Dogs: A Startling New Understanding of Canine Origin, Behavior, and Evolution by Raymond Coppinger and Lorna Coppinger (Scribner, 2001).