My puppy kept chewing through various harnesses, either the straps or the adjustment sliders or both. With this harness, the way the front padding continues along the neck strap area, and the width of the center padding, has so far defeated his attempts to get at the straps and sliders. No harness is chew proof, and we do not leave it on unless we are with our puppy, but he managed to chew through other harnesses despite these same conditions so we are very happy with this harness. In addition, it is well made, the buckles are secure and the two connection points for a leash help with training loose leash walking.