My aggressive malamute?

My alaskan malamute has a problem with a erspaniel that is owned by my father in law. She has no problem with other dogs, they are both female. The alaskan was introduced into this house as a guest, and the er gets cranky and growls or scowls at the malamute when she gets close to smell her. The problem that bothers me and my family is that it seems that the malamute doesn't want to stop fighting when she pushes her dominance on the er, we end up having to pull her of of the er, and it is becoming more frequent. What should we do?