When to change to adult food

[Laura]

I feed the kids Nutro Ultra holistic large breed puppy formula. (i switched from pro-plan a month or so ago) Shug will be 7 mos on Jan.16 and weighs 51 lbs and Chloe is 15 weeks and weighs 28-30 lbs. My last vet visit my vet told me to switch Shug to adult food between 8-10 mos. I trust my vet but was curious if any of you did the same...took yours off puppy food before 1 year? Neither is over-weight but Chloe is a solid little muscle mass it seems. Just curious.