OK, first of all, stop thinking of this problem as "FOOD guarding" and start thinkng of it as "RESOURCE guarding." You have said that she will guard her food bowl, as well as treats (and crumbs from treats), as well as bones. I would say she will probably also start guarding your food from the other dog, possibly water bowls, then sleeping spaces, then YOU (you are a resource), etc. It's WONDERFUL that you're feeding them meals in separate crates, but you must make sure that ALL their resources come when they are alone - NO bones, NO toys, NO training, NO getting on furnature, NO walking out doors, etc., or you will continue seeing the problem escalate. Also, I know that it is the first thought to punish guarding, by pinning, hitting nose, prying mouth open, taking food away, etc. But remember WHY she's guarding - because she's afraid that the resource will be taken away from her. Punishing this behavior is only going to CONFIRM that the resource will be taken away, and that possibly other bad things will happen as well, and the behavior will escelate. You're very lucky that you haven't been bitten yet - don't wait until it happens to decide to do something different. The book Mine! is, I think, the resource guarding bible. Jean Donaldson describes in great detail why dogs guard, what guarding looks like, what they guard, and of course, how to fix it. Basically she explains how to change the association from "bad things happen when the dog walks past my bowl" to "GREAT things happen when the dog walks past my bowl!" Note that this is different from "Nothing bad happens when the dog walks past my bowl, UNLESS I guard my food" which is what you're expecting your dog to learn if you punish the guarding. I highly agree with the majority of the advice above, especially the part where Athena wears a tab or leash all the time in the house. Management of resource guarding is the most important thing to do right now, that is, until you have a clear training plan in place for fixing it, and a leash is a great management tool. You can hold the leash to keep her away from the other animals if she is acting aggressively, and she will be less likely to turn around and displace the aggression to you since she doesn't directly associate the leash with you.