Dog owners amazingly put up with a variety of problem behaviors in their canine companions. But one problem that can be extremely upsetting and make an otherwise affectionate dog repulsive, to even the most tolerant of dog owners, is a dog frequently eating fresh stools of other dogs or their own, known as canine-conspecific coprophagy. This behavior, with the foul mouth and all, can be a barrier to the human-animal bond and impact the use of dogs as assistance animals. A visit to dog-related websites shows great interest and 11 commercial products marketed for the problem. Veterinarians are frequently asked about this problem. Explanations from authorities vary and there is no established medical explanation of the behavior. To obtain statistically valid information directly from dog owners regarding the behavior, two web-based surveys were launched, each yielding about 1,500 usable returns. A major finding was that 16 percent of dogs are frequent stool eaters. There was no link to diet or compulsive behavior. A surprising finding was that stool-eating dogs overwhelmingly went for fresh stools – hence the smelly breath. None of the 11 commercial products marketed for the behavior was effective, nor were various behavior modification techniques. Detailed data will be presented regarding these dogs’ coprophagy as described by their owners. An evolutionary hypothesis linking this behavior to intestinal parasite prevention in ancestral wolves will be presented. Since no treatments currently are effective, new treatment options are being explored to eliminate this stool eating in dogs.