I got a pitbull from the spca a few months ago. He was originally surrendered due to financial issues but his second surrender was due to the person being unable to handle him.
He has a few other issues like wanting to attack the cats and the sheep and he bites severily when I sometimes pull him at the collar (usually when he doesn't want to go outside or through the gate or when he chases the cats or sheep), but other than that I have not seen any aggressive behaviour, not even with other dogs or complete strangers.
The other day I wanted to spray him with fly spray and spray wound spray on his ears where the flies got to him, and he went absolutely crazy. He growled and snapped at the can as well as bit it a few times and his eyes went crazy, like he was a different dog. He became vicious.
I have hosed him down before and he only cowered a little. I don't know if he's ever been fly sprayed and if he's just deathly afraid or if something happened with his first adoption, but this is an issue for me as I don't know what other "vices" he may have that could be dangerous to family members or friends. I also don't want him freaking out when the need for a vet visit arises.
What can I do to correct or eliminate this reaction?