I got a CET Pet Toothbrush from a pet event. I have a 12 lb terrier mix (with a little mouth). I have found toothbrushes of all shapes and sizes, and I just need a simple one that will do the job. Since I have been using CET products (toothpaste and dental rinse) and that I am very pleased with them, I decided to stay with the CET brand. I like that these toothbrushes are small with a reasonable length handle. It allows me to brush my little dog's teeth easily, especially, getting to the back teeth. It is recommend that the pet toothbrushes should be replaced every 3 months, same as toothbrushes for human. Every weekend, I also clean it in the dental cleaner like Polident that I use to clean my retainers and night guard. I searched on many websites, and PetHealthMarket.com has the BEST price on these toothbrushes.