My five year old mixed breed dog had a bad rash on her belly and back. I read about acv from this web site I gave her 1/2 tsp in her food. The next day she had horrible diarrhea and she vomited soome blood. I took her to the emergancy vet and they did all sorts of tests and found nothing. The vet said it could have been the acv. That was the only thing different in her diet. I DO NOT recomend acv for dogs!