This toothbrush is very easy to use, just insert it into your finger and rub it in your pet's mouth. Its reach is wider and it can follow the furrows of our pets. Studies show that 98% of dogs with bad breath suffer from gum disease, a result of plaque buildup. If left untreated, it can lead to a bacterial infection, which can enter the bloodstream and spread to your pet's kidneys, liver, heart, and even brain. It's possible that because your pet has extremely bad breath, there's a problem with his teeth. Feeding your pet dry food is one way to help keep their teeth healthy, but the safest way to keep your pet's teeth in good condition is to brush them. Many liquid products claim to do the trick, but it's the mechanical action of brushing that really does the trick.