Unfortunately, I’m not personally experienced with bonding, but I believe the correct action to take is to house them separately and begin switching litter boxes and toys so they can adjust to sharing territory/smells. If they are civil,they can continue bonding sessions in neutral territory, but not in each other’s territory until they’re used to sharing space.

I know when a massive fight like that breaks out I’ve seen a lot of people completely separate them, as buns can hold grudges. There was someone on the forum a while back who had a similar issue, and needed to have her buns in separate rooms to forget each other.

Also, how much time did you spend prebonding them and letting the new bun adjust? A few months for the new bun to adjust to her new home and environment can make a difference because bonding can require that the buns trust you, especially if a fight breaks out. And prebonding gets them used to each other before just being put together even occurs.

i wouldn’t put them together again until they haven’t been around each other for a good month. It gives you time to bond to the girl and let her adjust to her surroundings. It also allows you to prebond and switch them between the two cages and switch their toys and litter boxes around. Patience is such a major factor when bonding. You really need to move at their pace, not them moving at yours.

Sorry but you need to completely stop and start over. You went too fast unfortunately. The seriousness of their fight means they will keep fighting until you give them time to forget. Since they have fought so badly, there is no guarantee they will bond, but if they are to, they must have time to forget each other and slowly build trust again.

Separate them as much as possible for three months, block their sight of each other if you can. Separate rooms would be ideal, so they are also mostly unable to smell each other. No pre-bonding or anything, do not let them interact with each other at all, even through a cage wall or a barrier.

Then do pre-bonding for 1 month. That means house them close to eat other, and swap cages every day or two. This will help you boy lose track of what is “his” territory. Still do not let them interact, but they can see and smell each other through fencing. Make sure they cannot nip each other. Feed them at the same time near each other as well. This is all working to build trust between them.

Then, you can start sessions again, in completely neutral space (so an area where no bunny lives or plays in). Start short, and DO NOT LET THEM FIGHT. You must stop all aggressive interactions before they escalate. I have a studio apartment, and I’ve used my bathroom for dating, as well as a pen set up in my office or at a friend’s house. You can also try stressing sessions, such as a car ride in a bin (with a helper to supervise), or in a laundry basket on top of the washing machine. There are many techniques to try, but all involve stopping fights before they happen.

Start short, and work up to longer sessions. When they can spend 4-6 hours in neutral space with no negative interactions (chasing, lunging, nipping) and lots of positive (grooming, snuggling, food sharing), then you can progress to semi-neutral. Once you are up to long sessions in semi-neutral with no aggression and lots of positives, you can move them to their shared space. You should not just put them straight into one rabbit’s cage. You’ll want to clean with vinegar and re-arrange the area so it looks like a “new” area for them.

It does sound like they would have been an easy bond, so I wouldn’t loose hope, you just skipped some steps so the fight happened. Imagine meeting someone on the street, and everything is going great, but then they show up in your house and are like, “I live here now!”. You might be mad too!

Keep us updated, and good luck.

PS. Love your avatar!

You moved way too fast as it doesn’t sound like you did any pre bonding or even let new bun settle in? You need to give penelope time to settle in her new environment, then begin pre bonding. Only after sufficient pre bonding can you do an actual introduction. And it must be on neutral territory – you can’t just plonk them together in one of their cages.

But for now, they need complete seperation. They’ve fought. Badly. They need to forget about each other which means they shouldn’t be able to smell or see one another.