I have a dog that is on Pro Plan Performance who will not stop eating poop.

Suggestions?

IMHO the type of food has nothing to do with it. Pick up up before they can get it is the best remedy but if you do a search here....you'll get more poop on this problem! Good luck!

His poop or other dog's poop?

Dogs that eat poop, ARE dogs that eat poop. Food has nothing to do with it. If you have more than one dog, then the others will soon learn the Habit . And that is what it is , a Habit.

Solution: Pick up all poop everyday.
OR
Pick up all poop everyday!

If you scoop all the poop there will be no poop to eat, problem solved!

I too have a poo eater. I scoop my yard religiously on a daily basis and after each time the dogs go. This does nothing for the poop eater that still painstakingly patrols the yard, searching for turds. I would give nearly anything for the habit to disappear, as I've tried so many things, in hopes that she will stop.
I have accepted that she won't stop and continue my routine of picking up the yard, before she does!

Picking up does nothing for me. Mine follows the others around and catches it as it comes out...before it even hits the ground. I've tried letting him out by himself but this just isn't as easy as it sounds sometimes. I've come to accept that its just his dirty, disgusting habit!

This is what I did and it worked:
I separated the problem dog form the other dogs completely except the moments I could be there watching her and only after I picked up ALL the poop. I gave 1 banana a day to this dog and I also gave 1/2 banana to the rest of the dogs. After 2 weeks she was not interested any more and I let her join the pack again.
Anyway, a month after she was back to her old ways but not as bad.
I've tried all the other recommended things and neither one worked.

"Boredom is often implicated......"

http://www.responsibledog.net/corophagia.html

I too have a pooper eater, and I try and keep the yard clean. We only have 3 dogs anyhow, so not too hard. She likes to go after one in particular's poo, and never her own. Sometimes I miss a cleaning, or the husband does, and we look out the window, and there she is, I just look away, or go out and clean.

I'm wondering though, does it do the dogs any physical harm to be eating 'familar' poop? All of ours are on monthly Interceptor. If they get into our horses poo or cat poo I will worm them for tapes on occasion, too. They never eat dog poo from dogs they don't know, as they are always leashed when not at home, so I have full control.