Just today my 11 month old blue heeler mix Winston became aggressive over any toy or object in his crate. He hasn't been possessive before and I've always been able to easily take toys from him in his crate. Now when I try to, he snarls, growls, snaps, and lunges aggressively. He ran into his crate with his sister's toy and had a fit when I tried to remove it from him in his crate. He's done this twice today. However, outside he crate he releases toys and food without thought. What can I do? I've tried trading him for the item but he hunches in his crate and will eat the food while protecting whatever it is that he's pulled into his crate. As I said, literally yesterday I took a fresh marrow bone away from him in his crate and today I can't even take a sock out of his crate without him nearly biting me. He is un-neutered as well but we are fixing him next month.