Brand choice of food for 4 month boxer

Question
Hi..I have a 4 month old female boxer and a 5 yr old female english bulldog..When I adopted the boxer, she was eating Nutro Puppy food and my bulldog was also on Nutro..After researching food for a while, I decided to slowly change them both over to Merrick dry and canned foods..I introduced the food slowly to both, but they have had continually on and off loose stools since their food has been changed.The puppy has maybe one normal stool a day and then 2 looser a day..I had them both to the vet and they are clear of parasites, so I know it is definately the food.The vet stated that maybe the food is just too rich for them.They have been on it several weeks.I thought by now they should be adjusted.I thought I was doing the right thing by switching to what I thought was a high quality grain free food, but it seems that I have created a problem...I am just wondering if I should just go back to the Nutro that I was originally feeding or try another higher quality food...I just hope that I don't have the same results or make matter worse..Do you have any recommendations of food choices???  I also heard Canidae was good, but I am a little reluctant to try another food at this point without a good recommendation...

Answer
I have used Canidae and it was excellent. I changed when I moved and couldn't find it.

The easiest brand to find at feed supply stores and "general feed stores" is Diamond.

I use a 40lb. bag (roughly $260 of Chicken and Rice. They also have amb and Rice, so you can switch up for a variation. It does not contain by-products, and does not have corn or corn meal. My Boxer is allergic to the corn product I believe.

She loves it fine (they offer canned too)...

Go to the Diamond web site and read it and you can search for a location nearest you. diamondpet.com

See what you think.

Slowly add to their current food. It should only take 1 week to change over if you do it right.

I believe their stools will change back to norm by then.