He doesn't get along particularly well with Loiosh, however he seems to like Vlad just fine. As a child, Vlad would frequently talk to Ambrus, and think that the cat was understanding him completely. For instance, turning around and swiping at the air anytime Vlad said "Look out, Dragon!". Naturally, later events in Vlad's life must surely have convinced him that Ambrus definitely did understand.
Rocza, on the other hand seems to get along better with Ambrus than Loiosh does.