Hi, I'm new to this forum so I hope my posting is in the correct area. I have a problem with a dog that has gone through some recent environemntal changes, and as a result, has become aggressive towards other dogs and cats (although it was never the case before). I have a 3 yr old male bulldog-mix (Mickey) and a 5-month old male husky (Shadow). For the past 2.5 years, Mickey and I lived with my parents. Mickey would go to doggie daycare twice a week, and loved seeing his daycare buddies. But just a month ago, I moved to a new home and got Shadow within the same week of moving. Mickey and Shadow are best buds. They love each other and are inseparable. Because the 2 dogs now have each other while I am gone to work, Mickey has not attended doggie daycare since Shadow was adopted. I suspect all the sudden changes have caused stress on Mickey. The problem is that Mickey - who used to be the friendliest dog - has now become embarrassingly aggressive towards other pets. I cannot walk both dogs at the same time, because Mickey will start lunging, growling, yapping, screaming, shaking, etc. at the mere sight of another animal. Mickey makes noises that I never knew a dog could make. It scares me and everyone within earshot! This makes Shadow upset, and he begins to dance around and howl. It's quite a spectacle to see. And I always have to cut the walk short and run home to calm them down. Also, Mickey has developed the bizarre habit of sneaking into the basement and relieveing himself. He refuses to use the backyard (even though he was 100% housetrained when we lived with my parents). If I block off the basement, he will hold his bladder for over a day and then eventually "give up" and go outside. But most of the time it still requires me pushing him out the door. It's almost as if he's disgusted by the yard. He refuses to walk on the grass. I suspect that Mickey's behaviour is caused by a combination of: - only seeing my parents once a week instead of every day - new home, new neighbourhood, new yard, new smells - thinking he's in charge of 'protecting' Shadow - no longer being at doggie daycare Did anyone go though the same thing after moving houses or introducing a new dog to the family? How do I correct Mickey's sudden aggressiveness? Thanks!