My breeder used NuVet with his dogs & puppies. I just continued to use it. My labbie is almost 3 y/o and has been healthy. I can't prove NuVet has supported his health, yet I would bet it has. I wish it didn't cost as much as it does, but I believe an ounce of prevention is worth a pound of cure (and less expensive overall). Nutrition is important, especially given I feed my boy dry kibble. I'm satisfied with the product.