My first guess would also be Brucellosis. I wrote quite a bit on this subject on one of the other threads. It is quite contagious and will move through a kennel quickly. There is no cure, but they can save the adults, need to treat with antibiotics. Will probably need to spay and neuter those affected though. This can ruin a kennel. Here is just one article of MANY online.
Dogs In Canada Magazine -- Brucellosis It specifically explains just as you have, spontaneous abortion and the green discharge.