Ouch! This is a touchy subject. While I love my yorkies, dearly, my children come first in my life. It is a responsibility as a parent to first look after and take care of their children. Sure, there are medications to control allergies but is it fair to keep a child medicated until:
A) The dog goes to rainbow bridge due to old age
or
B) My child moves out on his/her own
Sorry, but I can't justify keeping my child on medications for a dog allergy just so that I could keep my yorkies. Luckily, my children are allergy free and I really feel for those families that have children that aren't so lucky.
You're children's safety and well being are more important...JMHO.
Besides, what are the long term affects from being on medication all of the time? It could take years and years but I'm sure that something would come out of all of it.
I hope that no one ever has to make that decision. It is a hard one to have to decide. No one wins in that situation.