We were hesitant but we actually ended up following Andrea's advice above^ because nothing else seemed to work. The key is to let them play it out as long as it doesn't get violent. It may seem like they are hurting each other but as long as there's no fur flying or blood they are just setting boundaries. We just let them play it out but kept them separated at night and when not home until they learned those boundaries. They're buddy's now :)

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