Zoey has very bad breath

I had the same problem when I first adopted my chihuahua. Her breath was horrible and we tried the same products you did. When I took her into the vet, they said she just needed to get her teeth cleaned. It was a short procedure (I think I had to leave her there for 4 hours only because they put the dog to sleep while doing the deep cleaning). That solved the problem! The vet said they get buildup just like we do and it can lead to heart disease. I agree with the other answers - I would definitely take Zoey to the vet to see what they recommend.

I think since none of the other ideas have worked that maybe you should see a vet. They will check Zoey's mouth and see if it needs to be cleaned by a proffesional or maybe it's a mouth problem and needs attion. Please tell me if my answer works but if you don't want to take her to the vet call ahead and they should have proffesional advice.

I would have a good check up at the Vet certain medical problems can cause bad breath, kidney problems being one of them or your dog could ave gum or teeth problems that take more than brushing to fix

How do her teeth and gums look? Does she have a lot of plaque and tartar, and do her gums look very red and inflamed? It could be gingivitis, and if not nipped in the bud could be a very, very serious problem. I believe there are four or five "stages" to tooth decay and gum disease, and by the second or third "stage", its irreversible and you could have very serious health problems including becoming septic, which basically means an infection gets into her blood stream and can spread to her entire body.

However, it could also be dietary, but I do not have much information on that.

I STRONGLY suggest if you are brushing and trying all you can to improve her oral hygiene and keep her nice and clean and yet her breath is still bad enough to clear out a room, take her to the vet pronto. Gum disease is not something to be taken lightly and can turn very bad very quickly.