Hi Aspennn, welcome.
Lucky bun to have a new home !
It’s great that the pitbull doesn’t seem agressive towards the cage.
If he is obedient, when he is looking at the cage ‘normally and relaxed’ then that’s fine, but if his ears are in ‘alert’ mode (you know) or he is whining, then just nudge his side slightly so he changes the focus of his attention.
You can say NO too if he listens to that.
When he relaxes his ears or stops whining, that’s good. Repeat this until he stops his excited energy. he should then just turn and go away and not pay any attention if this is repeated and consistant.
I had a lurcher that was in full pointing mode when my rabbit first came home in the middle of the lounge in a cage….. it took 2 days of patient NOs before the dog gave up hope of a free dinner !!.
The first No commands, I saw her ears go back fractionally and then straight back up, her eyes remained fixed on the rabbit and her energy was in full alert….
Bit by bit the ears relaxed for longer each time, she started looking at me saying “WHAT? really? NOT dinner?” but then went back to ‘fixing’ on the rabbit.
Then a day or two later, one final ‘NO’ look from me and she lowered her head, turned away and sort of said ‘OK I get it, she’s one of us’.
Next stage, rabbit out on my lap and cat and dog were allowed to sniff with a relaxed energy (any excitement was met with a NO and finger point from me), and then next stage rabbit hopped around on floor….. with me in VERY clear site of the dog who had by this point realised that this was not a free lunch.
That was the turning point and they continued to share the same space until dog passed away.
Of course, be careful at ALL times – I knew my dog back to front and inside out and she was very obedient. If you doubt even just a bit, don’t push it.
But definitely stop the whining (from both dogs) with a NO or a touch (Cesar’s way! LOL) and keep them relaxed whenever near the rabbit…
GOOD LUCK and let us know how you get on !! :o)))