I would definitley take him to the vet.. I don't mean to scare you, but those symptoms sound like what Brooke had before she had to go to the doggy ER. Brooke wouldn't eat or drink anything, kept throwing up, wasn't acting like herself, was always panting and crying and just wanted to go outside and sleep in the grass. She wouldn't really respond to any of us. I would take him in to make sure there isn't a problem.. you can't be too careful..

By the way, what kind of medicine is Angus on?