If you don't have any luck with fragaria try Petzlife gel. I've been using it for just over a month and over the last couple of days have been able to pick off the tartar from my old boys teeth with my nails. (He's 12). Its all natural ingredients and you just rub it on their teeth and the saliva activates it, and it softens the tartar.
The thing you have to watch with fragaria is because its homeopathic, it's supposed to go straight on to the dogs tongue without touching your hands, as any sweat apparently affects its potency. We used to tip the tablet onto a piece of paper, fold it and crush the tablet then pour into the mouth. Have to say this new gel is so much easier, and the results much quicker, and I would definitely recommend it. There are before and after photos on their website, and I really wouldn't have believed it without seeing it myself.
