@imbadatmakingusernames You definitely are. He thinks/smells you're nervous about the other dogs and goes into protective mode on your behalf. If you tell him it's ok then you're reinforcing his behavior.
@word_cuts_deep Somebody at home is sneaking her food. Take all of them to the vet when you go so the vet can tell them what's up. The guilty party will either get mad or look away etc. Bring me the dog and I will get him eating. No problem.