how to rebond brothers after stay at vet

Question
I have 2 neutered 9 month old dwarf lops. They used to be best friends and inseperable. Unfortunately one had to spend a night in the vets for gut stasis. Luckily he made a recovery and came home the next day but now hes become agressive to his brother. Weve tried rebonding them in a neutral room which went well and when we put them back in a semi neutral space they were cuddled up together for periods before him turning on his brother again. Ive also tried wiping them down and cleaning all their cage and accessories to remove any scents of the vet and provide a more neutral environment. They go for periods of 5 hours of being friends, snuggling together and grooming each other and then the one thats been in the vets attacks his brother who never retaliates and acts completely subserviant. Dont know what else to try? They used to get on so well and would hate to have to keep them seperate when they used to be such good friends!
Thanks
laura

Answer
Laura,

are you sure this isn't establishing dominance as opposed to outright fighting?  If he's the dominant one he's just reasserting it again.  It sounds like the other has been the submissive one before.  Unless they are actually fighting for real, as opposed to chasing, pulling out loose fur, and mounting - all of which are dominance moves - this needs to occur again before the relationship can go back to normal.

If they are getting along for 5 hours and then this happens, I suspect it isn't fighting.  Fighting would be really bad and would not stop until you actually removed one.  Rabbit fighting is biting at face, ears, belly - kicking with hind legs, growling, charging with teeth bared ready to bite.  Not chasing, pulling loose fur, mounting.  

I think your dominant boy just wants to make it clear to the submissive one he's still the one in charge.  And in 2 or more rabbits, one is always in charge.  It doesn't sound like the submissive one is challenging him so it will probably go down after a few days.  The thing you'd need to watch for is a case where both want to be dominant because that's the situation where things could escalate into fighting if one doesn't back down.