No need for a small dog to be on puppy food very long, IMO. If at all actually, if you can find an all life stages food. Depends on the food but most foods would suffice for puppies -- puppy foods mostly just have higher protein, fat, etc. The only time you have to watch out is in large breeds with the calcium/phosphourus levels but that is not a concern with little dogs. Plus most small breeds seem to be done most of their major growing by 6 months old.
Jackson started eating an all life stages food at 6 months old. But then I mostly believe that puppy/adult/senior/breed specific are all a marketing scheme. But I am glad for all the options out there, catering to different dogs needs.
