PetGuard® Herbal Collar for Dogs is a scent collar to keep your dog smelling fresh and clean. The natural herbal essential oils of Pennyroyal, Eucalyptus, Cedarwood, Citronella, Rue, Rosemary and Lavender are impregnated directly into the collar. Our herbal collar is safe for all dogs. Every collar is a natural blend of aromatic herbs, with a fresh minty fragrance and absolutely no harmful chemicals.