Veterinarian's Best Tear Stain Guard Pet Swabs make caring for your pet faster and easier than ever. These cotton-tipped swabs are filled with liquid that prevents new tear stains and gradually fades existing stains. When you snap the end, the liquid flows into the cotton tip. Simply wipe the desired area and dispose of the swab. You get a fresh, accurately measured treatment every time. Mess free and easy to use, just snap the tip to release the liquid. For use on dogs. and cats.