recognizing when play is not play.

Question
Hi Kim,
I have two standards.  Abby is confident, Donnie is fearful.  If I let Donnie play with submissive dogs, within minutes she will start barking, jumping back and fourth and nipping.  Donnie will not get this excited with a confident dog.  But if there is a dog meeker than she, Donnie will "attack".  My question is what makes her want to do this.  And how can I stop it?  Thank you so much.  Your advice is always so helpful.
Kim, Abby and Donnie.

Answer
Hello Kim, Abby and Donnie,
Donnie is most likely doing this because since she is also a submissive dog, she likes getting to boss a less-submissive dog than her around.  It makes her feel better so she takes every advantage.  You need to let her see that she can't act like that around other dogs even if she is more dominate than they are.  
In this case, you need to make her submit to the other dog by making her lay down, and let the other dog come up to her and smell or stand over her.  Get on to her if she growls or acts aggressive.  If she is playing nice, don't bother with her, but make a big deal if she gets too rough.  You can also bring a spray bottle or a shaker can (can or bottle with pennies or rocks) and use it when she starts getting rough or wants to attack.
Be sure to use a deep voice and sound like you are growling at her.  She needs to know that you don't approve of her behavior.  

Try this and if you have other questions for me, just let me know.  

I hope you all Have a Wonderful Howlday and a Super New Year.
Kim and my Zoo Crew