I have 2 male basenjis 12 years, 11 years, one female basenji 2 years and one female malinois 17 months (acts about 7 months) and haven't had any real problems. Jet, the tri-ing, my 11 year old, is a bit grumpy inside, but enjoys playtime outside. He has lots of rules about indoor behavior and growls a lot, but, sadly for him, nobody pays much atttention to him (except the current and past malinois who both act a bit afraid of his growling). So, he growls, acts real tough, but has never hurt anyone. Digital, the brindlewonderkid, my 12 yo, is more playful and is a very tolerant gentleman. So you'd think my Zest puppy, is going to rule him, but every once in a while he'll put her in her place and she kowtows to him quickly (unlike with Jet, who she usually ignores him when he tries that).