Rose B-
Breeders are not doctors or researchers and only can do what they believe works for them. A regular puppy formula is not meant for a giant breed puppy. This is probably what was being fed to the dog with H/D. Or it was genetic. 30-40 years ago (when your breeder started breeding) there were no appropriate puppy foods designed for large and giant breeds like Mastiffs. Now there are more than enough. Even my teacher (who graduated vet school over 30 years ago) used to tell her clients to feed adult food to giant breed pups. Now she said, she absolutely does not. Too much research to prove the harm in doing so and with all the great large and giant breed puppy foods on the market, she does not agree with that anymore.
