Roxy has been acting agressive recently and Im wondering if she might be going into heat? She barks at me and my boyfriend and that is something she NEVER used to do. If we are eating dinner and she is trying to jump in our lap and we tell her NO! she will sit down and start barking at us!

We put her in her timeout xpen but the moment we let her back out and she does something she isnt supposed to do and we tell her NO! she will bark right at us again! Has this happened to anyone elses yorkie??