Riley was my first Bull Terrier. She was so energetic and always on the go. She was a play biter and bit really hard, but I attributed that to the fact that she was deaf. When puppies are with their littermates they learn to not bite so hard when they hear their littermates squeal. Riley never learned that because she couldn't hear the other pups cry. Because of the hard play biting issue, I kept her away from my niece and nephew because I didn't want them to get bit and then be afraid of dogs. We were going to go to obedience classes after she was spayed, but sadly she died 10 minutes after her spaying was completed.
Mirra is my second Bull Terrier and is almost 4 months old now. She's going through a biting and teething stage but is learning to not bite so hard. She's great with my niece and nephew and hasn't bit them.
Both play(ed) quite hard, but where Riley was constantly on the go, never taking naps and not wanting to miss anything, Mirra will play hard and then cuddle up on the couch with me and nap.
They are clowns. Riley more so than Mirra, but they race around the house with a silly grin on their face and bounce off the furniture. At one point, Riley had been racing around, went to jump on the couch and completely missed it and crashed through a window.
I would say that Riley was more energetic and crazy than what Mirra is now. Mirra is more lady like and a little more laid back.
They are very stubborn. I've told both of them NO so many times and they don't want to listen. In Riley case I shook my head NO so much that I thought I would suffer permanent neck damage.
Both love(d) to chase cats, but I think that's something all puppies go through. Plus, it would help if I had a cat that would actually stand up for itself. Hobo runs and hides in the computer room and Jag just lets himself get mauled. On the plus side, when Mirra gets ahold of Jag she just lays on top of him and doesn't bite.
Health concerns: Deafness is extremely common in the white ones. Kidneys need to be tested yearly with a simple blood test. Some Bull Terriers have a zinc deficiency or can't metabolize it at all. And, as I just recently and sadly learned, there can be concerns with the heart. Riley's heart was found to be defective and didn't function correctly which completely amazes me because she was constantly on the go and wouldn't slow down. Mirra will be going to see a dog cardiologist later this summer just so I'm not so paranoid. I've also read that some Bull Terriers are very sensitive to anesthesia because where most dogs have fat, bullies are mostly muscle and metabolize it differently.
Another health issue is obsessive/compulsive behavior and spinning. I was seeing signs that Riley was a spinner when she was about 6 months old. It started off as tail chasing and then went to just flat spinning in circles whenever she was bored or overly stimulated. I managed to curb the behavior somewhat by telling her NO or distracting her, but I think that could've become a big issue down the road. I've read that alot of Bull Terriers become so obsessed with spinning that they will do it for days on end. No eating, drinking, or sleeping....just spinning and their owners couldn't stop them or distract them.
Another thing is that they are VERY strong, even as young puppies. Riley came barreling at me full speed this past winter and knocked me down (to her advantage I was standing on an icy spot, but she still knocked me down). More than once she took off running when on her leash and caught me off guard and I thought she almost yanked my arm out of my shoulder.
If you haven't already discovered it, the initial cost of getting a Bull Terrier is a bit expensive.