I have a year and a half old corgi named Zaza, and I'm pretty sure she has food aggression. She tenses up when we're around her food, and growled and snapped at us when we pet her or have our hands near her. She's also gone all day without eat her food and we'd find her toys covering the bowl. This has been going on for about half a year now.
I admit we probably made mistakes when we were trying to deal with it. At first we'd physically step over her food and make her sit and wait before she can go at it. If she still snapped we'd put her on her back. (I know and realize soon after that I shouldn't have done that) That wasn't helping so I did some research online and tried a couple of solutions I've found.. I tried feeding her by hand, but she wouldn't eat it. The newest thing I'm trying is to feed her in increments with me in the room. I saw this on that show "it's the dog or me" or something on Animal Planet and the dog portrayed a lot of traits and problems as Zaza. It's kind of working, but she still takes a long time to even eat the first couple of kibble. She'll take one kibble and take to a corner, leave and come back and stand over her food, watching me out of the corner of her eye.
She has the same problem with her kong ball that we fill with treats to keep her occupied, but recently she'll just lay next to it and when we walk past she'll stand over it tensely.
When we would crate train her, near the end of the crate training we notice she would snap and lunge at our hands at night, but not in the mornings. Same when we would fence her in the kitchen with the baby gate and she would snap at our hands when she would be sitting next to it.
She doesn't have any problems with us taking her toys from her or objects from her mouth. I know I've made mistakes and now I want to know how I can fix this.