Sgt Reckless Horse Grease is a thickened mineral oil that keeps horses and other large animals from chewing on surfaces. Horse Grease is water and heat resistant, so it's good for year-round outdoor applications. Paint the grease onto the surface you want the animal to stop chewing. Works on horses, cattle, donkeys, mules, alpaca llamas, pit bulls, large dogs, small dogs. Testimonials are available.