I have been using Duramune for years now on my pups and adults... As a breeder, I can say this product is tops.... The product is easy to deliver, and none of my dogs have suffered any adverse reactions to this vaccine....All chippy,and running around the next day.. The quality is second to none! I am delighted to have this vaccine available...and will continue to use it with the utmost confidence! A great big" thank you" to the scientists that developed this vacine!!