[theBCnut]

The skin pH on a human is close to the pH of a horse’s skin, so they can trade shampoos without issue. Dogs have a different pH, so human or horse shampoos may cause a problem in sensitive dogs. However, that’s pretty rare and I rinse with a cup of vinegar in a gallon of water anyway. I’ve never had a problem with using vinegar and water on my own hair either, which is not the proper human pH.