Hi and welcome to YT. "When" I had puppies my vet advised to change at 1 year old. It is always best to seek advise from your vet, he / she knows your pup, has pups medical records. What works for one persons dog may not work for yours. I would stick to what my vet advises. Good luck.
__________________ Joan, mom to Cody  RIP Matese  Schnae  Kajon Kia  forever in my  A House Is Not A Home Without A Dog |