Well.. My old Chihuahua mix Boogie is a huge bully to my new Chihuahua mix Enzo... And its at random times, they get along great about 70% of the time.. But the other 30% Boogie is just plain nasty to him, attacking him for no reason at all.. stealing his treats (EVEN tho Boogie has his own treat) or when Enzo is sleeping Boogie will sneak up and attack him, Enzo just cowers and barks and cries.. I don't know how to discipline Boogie for his actions..I don't want him to be (anymore) resentful of Enzo.. I don't pay more attention to Enzo than Boogie, Enzo is pretty much my Moms dog and Boogie is my dog.. & Boogie got along wonderfully with our Cat before he passed away & never acted this way towards him... Any advice? (We've had Boogie since August 2008 and got Enzo September 2010)