Collagen is a popular ingredient for dogs, especially for joint issues. However, not all collagens are the same, and it's essential to choose the right one for your dog's specific needs. This article provides a vet's opinion on the difference between hydrolyzed collagen and undenatured type II collagen, and which one is better for joint health. With clear explanations and scientific evidence, pet owners can make an informed decision on the best collagen supplement for their furry friend.