We recently got a German Shepherd/Terrier/Blue Healer mix (they think that’s a what he is). Today he aggressively attacked my Chihuahua. I didn’t see the first time it happened I was coming around the corner but I’m pretty sure it was similar to the second time it happened today. He is trying to play with my Chihuahua and he didn’t want to play so he nipped him. Our puppy instead of backing down went into a full blown attack mode. Had the Chihuahua pinned and had him by his neck. This happens in a matter of seconds. The first time I grabbed the puppy and put him in submission. The second time I grabbed him and put him in his crate. This was not done very kindly. I’m at my wits end Michael my Chihuahua is 10 and only 6 pounds Jeffery our puppy is probably 10 plus pounds. Pleas help.