About two weeks ago, Henry suddenly began to show possessive aggression. I was totally blown away by this behavior as he has been the sweetest and easiest pup I've ever had and was a breeze to house train and crate train. His obedience is really good and I abide by the rule that "nothing in life is free". He has been CC'd to "here" as he had a tendency to go and visit the gunner rather than return to me. He has also been doing well with the "hold" and I'm about ready to start FF.
His aggressive behavior first showed up a couple weeks ago when he grabbed a scarf off the floor. Normally, I could go right up to him and say "out" and he would drop the object. Not this time, he took off running and when I was able to catch him, his body became stiff and he started growling and snarling at me. I was able to get the scarf away from him by just waiting him out. Last Sunday was the worst incident thus far. I tried to get a toy away from him by telling him to "sit" and "out". I took a hold of his collar and he proceeded to bite my hands, arms, and leg. I was prepared and wore leather gloves, so luckily only ended up with some really ugly bruises.
I am so surprised by his sudden aggression as he is a very happy and social puppy with people and dogs. I just have no idea where this aggression came from. I get conflicting suggestions from people such as to pin him down until he submits or trade him his guarded object for a food treat.
I had really hoped Henry would be my first MH but with aggression rearing its ugly head, I'm not so sure any more. Can this behavior be corrected? (I have to admit that I am now nervous about taking any object away from him.)
I am really upset about this so any suggestions would be greatly appreciated.