Question Will neutering my puppy at a young age stunt his growth?

Answer Dogs' size is mostly determined by their genetics, not their hormones. Neutering does dramatically reduce the amount of testosterone in a male pup's system, which may give him a bit less muscle mass in the long run, but won't affect his height or the size of his frame. Actually, studies have shown that dogs spayed or neutered early (at 16 weeks or younger) tend to be slighter larger than those altered later in life. So no, you won't change your dog's growth by neutering him as a puppy. Plus there are a lot of advantages to neutering your pup. For more information, see Neutering Your Pet.