Very good stuff!! My dogs drink it in their water with no problems. Their teeth look great.When i put it in my dog's water he wouldn't drink the water.Didn't appreciate seller signing me up for a subscription I didn't ask for.Didn't really see much plaque off my Yorkie teeth.Helped her foul breath but needs to be continued. Needs better plaque remover.My Moose is picky when it comes to flavors.He loves mint and drinks his water right up.It's easy to doseI am done with this stuff. The manufacturer CANNOT get its act together around quality control. So many bottles have visible mold in them, it's really hit or miss if you'll get a clear bottle or not. And even if the liquid is clear with no visible junk floating in it - does that mean it's really okay? Who knows? I'm really disappointed, because it was working so well for my cat. But if I can't trust the purity of the product I'm not giving it to her. I've adjusting my rating from 4 stars to 1 star.My original review:I have a Maine Coon who is prone to gingivitis. Having lost another MC to anaesthetic during a routine dental cleaning, I am very interested in any product that might prevent or delay dental problems requiring veterinary intervention. This cat has also had some gastrointestinal issues after a parasitic infection as a kitten.So I was excited to find this product, and started adding it to my cat's drinking water. I had to resist the urge to check her teeth every day, but after several weeks I saw remarkable improvement, and a few months later her teeth are now sparkling clean, her gums are healthy, her breath is great, and yes, her poop smells much less (it was pretty stinky before). She showed absolutely no negative side effects.But then I read some of the reviews here and elsewhere on the web regarding two of the ingredients: anthium dioxide (a.k.a. stabilized chlorine dioxide) and sodium benzoate, and they freaked me out: what have I been giving to my cat? So I started doing some research. One thing I learned is that cats are more sensitive to sodium benzoate than other animals, and some cats may have a toxic reaction to it. Given how well the product seems to be doing, I think this must be pretty rare, but it's something to be aware of.After a lot of reading and some calculations of my cat's actual exposure to these ingredients in terms of volume per body weight, I've decided that I'm comfortable with the product, especially considering her genetic tendency toward gingivitis. But I should have done this research before I bought the first bottle.I have two pugs. Have been using this for years and my pugs seldom have any of that awful "pug breath" so many of that breed have. Since I have very hard water, I buy distilled water for them and add the Plaque Off to it. I'm not sure that it truly makes a difference, but I figure it can't hurt. (I see how the hard water clogs my shower head and kitchen sink nozzle...yuck.) My dogs get enough minerals from their food, so they don't need minerals from hard water. My oldest pug is 11. She does have some plaque, but my vet says it's a lot less than he typically sees in pugs, especially at her age. I do notice that they seldom drink tap water while we are traveling and do prefer this mix.No smell, no flavor, tasteless, clear. I use a bottle attached to his cage for 80+% of his water and he doesn't even know it. Has the nicest white teeth of any dog I know. Use brushing chews too - never any dental problems and he was 6 years old yesterday.