Finally, no more poop eating.
After trying every product under the sun with no help we finally broke down and bought a remote shock collar for our dog after two years of severe coprophagia issues.
I was planning on getting a remote citronella one instead, but was advised that over time they can get desensitized to the smell and then the training no longer is effective. I thought for the longest time that shock collars were cruel but actually they are better then I was expecting. I can choose the intensity of the shock and tried it on myself first, feels more like a tingling sensation, no pain and extremely short, just meant to get the dog's attention to change.
This was a last resort choice as she was getting sick too often from this really bad habit. She started eating poop when she was two and has continued with it ever since. She eats hers and our other dogs, she has always been on healthy dry foods like Wellness, Innova, California Natural, Nature's Variety etc., so I don't think it's a nutritional issue for her, it's most likely an O.C.D. behavior thing.
We did try all the pills, over the counter and from the vet, the natural stuff like pineapple, meat tenderizer, hot sauce, and different training commands "leave it" etc, with no progress. Walking her on the leash all the time works and is what we did for a while, but it became difficult because she can take up to 20 min. to go potty while on leash (she's always been like this never going to the bathroom on walks), specially not fun on very cold winter nights or when you need to leave soon to go somewhere.
She's been using the collar for 2 weeks now and has been doing great, I rarely have to correct her with a shock and always try the sound button first, which usually works. There have been several successful times where she doesn't even try to get near the poop. I can go back to picking up poop outside every couple of days and not worry about her gorging herself on it. She only wears the collar when she goes outside to go to the bathroom and so far has let me put it on her without hesitation or fear. I'm hoping in the future she'll get to a point where I won't be correcting her at all except a few times a year if she starts to revert.
I've also heard that the wire basket muzzles can work as well, probably if you add a stool guard but her obsession is so strong I thought she would find a way to mash the poop through the muzzle and lick it off.