female shitzu aggression with newcomer

Question
we have 5 dogs 2 golden/lab males 1 yro., a mini blue dapple dashund (female) 1 yro, shitzu 1 yr (female) and now a found female pomeranian about 1 yr. All the dogs grew up together as puppies and now our shitzu hates the pomeranian and contstntly gets into vicious fights w/ her even when she wants to play. we have now put the shitzu outside and alternate the inside time. How can we get them to get along, or at least stop the fighting? All the other dogs get along together great, except the shitzu with the pom. I really dont know what to do. and we want to keep all the dogs. Also when the shitzu and pom would fight( really just the shitzu attacking the pom(the pom doesnt fight back) the dashund would get involved first by trying to stop the fight but later joining in the fight. But when they are seperated the dashund and pom are Best friends. Help! What should we do?

Answer
You have a lot of female dogs all about the same age. Realistically you will probably do best with controlled interactions between the two competing females. Maybe they can take leash walks together. If their only interaction is a special one that they both value then possibly over time, their view of each other would change.

But to be honest, I do not hold high hopes for all 4 being together happily without a huge effort on your part. Have someone come out and assess in person. Try www.ccpdt.com