increasing agression

Question
I have a 10y.o. spayed Shep. mix. About 2 yrs ago, I brought a 10 month old Beagle mix into the home and they played very well together until about 2 weeks ago.  My Shep. attacks the Beagle when she is out of her crate; the Shep gets on top, they fight, both showing teeth, the Beagle pees and eventually the Shep lets Beagle up.  Then the Shep started smelling and licking the Beagle in vaginal area all the time- it's like she starts the fight in order for the Beagle to pee or something.  Both are spayed.  The Beagle is now afraid to come out of crate or be anywhere near the Shep.  What's going on????????

Answer
The key to most behavior problems is approaching things using the dog's natural instincts.  Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog.  Life is much easier if the 2 legged pack members outrank the 4 legged ones.  You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/  For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm