Agression
 

Just rescued our Yorkie about 3 weeks ago and has been behaving fine. Now all of the sudden has started to be aggressive. When he is sitting on me or my wife's lap and I go near her he goes into attach mode. The same if he is under the bed or behind something and I want to get him out he gets aggressive growls and gets very aggressive. Is this a territorial thing or just part of the Yorkie breed ? All replies will be appreciated.
Thank You

He is being territorial and resource guarding. Be patient and maintain an even temper when dealing with the problem. Do not react in an angry manner.

When he displays this behavior while on your wife's lap and you approach, he should be put on the floor. You can just say his name in an "uh uh uh" type tone. He will learn that he can't be on her lap or on the couch if he doesn't behave.

Withdrawing attention can be effective in stopping unwanted behavior. I have 2 boys and they play a jealousy game. If one is on my lap and the other gets jealous, I put the one I'm holding on the floor. Then I ignore them.

Sometimes I get up and leave the room where they cannot follow. Within seconds, everything has returned to normal and we go about our business.

Work on basic obedience and trick training in fun way. My boys only know a handful of tricks/commands that they perform for treats, kibbles. This helps boost confidence and bonding, and minimizes resource guarding or territorial behavior.

Also helps with things like getting him to come out from under the bed. Rather than forcing a situation, lure him out in a positive way. Ask him to come out for a treat. Then ask him to perform a sit.

Victoria Stilwell, a positive reinforcement trainer, has more tips:
https://positively.com/dog-behavior/...urce-guarding/