C.E.T Hextra Premium Chews are clinically proven to reduce the calculus on your dog's teeth. Uses the antimicrobial power of chlorhexidine and the mechanical action of rawhide to provide immediate surface plaque removal and tartar control. Chlorhexidine is released into the oral cavity during chewing and may be released up to 24 hours, providing sustained antimicrobial action. The appealing flavor makes them easy to feed. For daily use or as an option when brushing isn't possible. Sorry, this product cannot be shipped to New Mexico.