Try putting water in with the food, that's what I had to do with one of my dogs to get him to eat slower. When there is water in with it, it's really hard for them to eat it too fast. Another great idea is to feed him out of interactive treat balls. It sounds like he might be doing a little bit of resource / food guarding, and this is the first sign of it. He's not growling yet, but he doesn't want you to take it away from him so he eats it faster. (again I said sounds like, I haven't seen it so I could be wrong). Along with doing the water thing, or one of the other ideas others have given, try every time you walk by, just drop a treat by him. He'll soon learn that it's a good thing when you walk by, you aren't coming to take his food away, but to give him a goodie
. Hope this helps! There are other things you can try with guarding food too, but I suggest trying this first. It might take a while, but he should start catching on. If not, let us know and we'll try to help you out further
. Thanks
~Amy~