I have a 7 month old dog and ive had her since she been about 8 weeks old. She's a beagle,shiz tu mixed. and it was just her and two cats. Then my cousin got got shiz tu dog. He end up not wanting it. So we took it and my dog fine with him, but alot of times not all time but a lot of times if im petting her and then he comes up and i try to pet him She attack him. I've broke them up alot? but there fine in least i pet him?

its because she luk at you like a mom. its like you having a mom and its just you and your mom then all of a sudden a new kid comes in and tries to steal her away from you.. shes jealouse!! try not to pay more attention to one more then the other(: just like youd do your kids, treat them with equality

Shes jelouse. She wants all the attention, and doesnt want another dog around you. lol