This is quite a controversial subject. As with many hypothesis, there are several schools of thought on it, but no absolute truth. My rational comes from my scientific research with probiotics (our group comprised of four vets, all PhD's, one nutritionist and one biochemist). We noticed, in lab, that 80%+ (I can give you exact numbers later) dogs on a wheat or corn diet, had less absorption of probiotics. When we checked the stools, the CFU count as well as mineral count were much higher than dogs on grain free (or at least wheat and corn free) diets, which leads us to conclude that they were absorbing less of it.
Clinically I also see that probably about 20% (rough estimate, not empirical) of dogs do OK with wheat, but an overwhelming amount do better without.
The other reason I'm not a fan is the lack of actual nutritious value. As 90% of the dog's immune system is in the gut, and YT's have only 6" - 12" of intestinal track (versus 26' in humans), which doesn't give much time for nutrients to get absorbed. In nature, canines don't eat anything that isn't necessary. All they ingest has a reason, a purpose. That's why I believe even treats should have a purpose.
I hope that clarifies my views.
Giulio Ferrari, MS |