Oliver has an upset tummy!

So I noticed a small pile of Oliver puke this morning after I got up... It was all kibble (mushed up of course, but I could see the different colors of his kibble pieces) and I made out the three little treats I gave him last night... now I don't know why he threw up - the only other time he's thrown up while I had him was after the first time I gave him kitty grass and he overindulged.... the ONLY thing I changed was adding dental freash to his water on Wednesday, so I'm thinking that's upsetting him.... should I remove the dental fresh water? Remix it so it's less than the suggested dose? I don't think he likes it, as I've only seen him drink a little and he goes nuts when I pour myself a glass of water (he always samples from my water glass, but now he's RUNNING over to my cup after I pour)... so all of this is making me think he does not like (and for that matter can sense - even though the bottle says they cant) the dental fresh!

Suggestions quickly please! I don't want Ollie's tummy to be upset!!

talk to the vet... The main reason I dont use the add to h2o stuff is the other aka inactive ingrediants..

Ok, so I just changed all his water dishes back to plain ol water, just cuz I'm scared and really think that's the problem.... I saved the dental fresh water in a gallon jug for after I get more advice from y'all... well as soon as I put the fresh water down, Ollie drank up - so I REALLY think the dental fresh is the problem... those of you who've use it: did you introduce it gradually, or just do the recommended dose immediately? I plan on talking to my vet at home next week about his dental health anyway and see what she suggests (as I always mention, haha, she's a trusted friend as well as our vet).... but until I get some more advice/info/suggestions, I guess I'll just stay with regular water....

Thanks y'all... Ollie NEVER gets sick, so of course I'm a little shaken and don't want to do anything to upset that little tummy anymore!

Awww, poor Oliver. There is a product called Greenies that's supposed to help with dental health and fresh breath. It might work better for him.

Dental Fresh Ingredients: Purified deionized water, stabilized chlorine dioxide, sodium benzoate, and organically derived chlorophyll.

Chlorine dioxide and sodium benzoate?