Hi, I pick up my Vizsla pup Otto on July 18th and have a couple of quieries about his diet. Otto's breeder is bringing him up on Vitalin Puppy Plus. I had been planning to switch him onto either Burns or Arden Grange but wanted to check if you thought this was necessary as I haven't really heard much about Vitalin either good or bad. If I do switch his food, how long should I keep him on the Vitalin while he settles in before I start to change his food over? Thank you for any help.