There's also no better way to kill your dog. Well, there probably is but the ingredients in Listerene (especially ethanol) are pretty much poison to dogs.
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Just try a different brand of dog food. I feed my dogs beef and chicken mince, with dog biscuits / standard processed food in some cases and their breath while not the most charming thing in the world isn't that bad for dogs.
They aren't meant to smell as sparkly clean as humans prefer their breath to be though.
