I feed a store brand, plain, low fat yogurt. I'd prefer the fat, but they don't have it.

As for worry about sugar? I don't. I don't see any sugar coming from any other source. On top of that, there are two containers being split b/t 12 dogs for only 3 days per week. It seems to be enough to reap the benefits without it being too much of anything negative or in cost.

I buy my food tomorrow, so I'll check the sugar content and get back to you with more info.