One of the weak electric powered ones might be safe and quiet enough for equine use, but I'll stick with the good old garden hose and hard work just to be safe, no matter how tempting it is when I see her with mud dripping off, beats when it's baked on though.Might be safe - with a "just right" nozzle. Wouldn't trust many to get it right, though. I can just see some idiot trying it and ending up with flayed horse...