Frustrated aggression Cocker Spaniel
I have a 10 week old working type Cocker Spaniel. We have 2 other dogs. So far I have been very pleased with how everything is going. He typically stops mouthing me and my partner when told to instantly. He doesn't react when anything is taken away from him. He has been showing respect and responding very well to training. He avoids my 9 year old GSD mix as she doesn't want to play with him and knows where he stands. My younger mixed breed (Jake) loves playing with him. On this occasion the pup was getting very rough when playing and I noticed Jake was not happy and snarling (but not growling), the pup either did not notice or didn't care. I would usually let Jake tell him off himself when he gets too much but as I wasn't comfortable with the situation I intervened. I picked up the obviously hyperactive puppy and held him for several seconds in an attempt to calm him down as he wasn't listening/understanding our vocal commands to stop. After a few squirms he quickly turned and snapped at me, biting my hand.
I would like to know how I should have dealt with this if I did something wrong and how to address this as I'm sure he's going to have to be restrained in other situations in the future. He is comfortable with being held and loves cuddles so as far as I can tell it was just the frustration of not being able to get away. He also wasn't startled by me picking him up. Thanks in advance for any advice.