Most dogs have no problem with a Shungite Pet Pendant because they normally have collars on. Cats can be another story concerning the collars. If they do wear collars, we recommend using the resin pendants for cats due to it's smaller size rather than the wire wrapped pendant. Putting Shungite nuggets in water bowls (3 per water bowl) will benefit all pets. Shungite products brought into a home environment will benefit pets as well as humans.