My rabbit became aggressive after being spayed

[Sayuri Nakashima]

Hello! I have two female rabbits, Nene and Kuu, that are about three years old. These two are sisters and they used to constantly be next to each other, grooming, and sleeping together. There were times when Nene would chase after Kuu - she never fights back - and that was when we decided to separate their cages, but we let them out together.
However, after being spayed, Nene became even more aggressive even though we thought it would calm it down. Every time she sees Kuu, she would try to chase and bite her as we try to stop it. We stopped letting them out together after seeing this as Kuu also bled once from being bitten. We thought it would calm down in a few weeks to a month, but it did not as she still chases her when we try to make them bond again and it has been half a year since the surgery.
Now, we let one bunny out an hour, switch it to the next, and repeat. I am just wondering why Nene became more aggressive even after being spayed and is there a way for them to bond again? Just letting them out together would only result in Kuu being chased (even after being stopped, she'll do it again). We just miss them being together, and it looks lonely when they are by themselves. So if anyone knows a solution to this, that will be amazing!
Thank you

 

[JBun]

Once rabbits have been separated for a length of time, they usually have to be completely rebonded. Have you tried the actual bonding process? It's not entirely unusual at the start of bonding for there to be some chasing. You just don't want it escalating into excessive chasing or humping, or circling and a fight.

There are two basic methods of bonding, the fast method where you start and don't stop til they are bonded(usually 24-48 hours for the main bonding, though could take longer) and the slow method where you do short bunny dates each day. There is also using a small(2x2,3x3, etc) area or using a larger area. What method and what size of area is best really depends on the individual rabbits being bonded. One method and one size of area may work best when the other won't. Here are a couple links on bonding, but I would suggest doing thorough research on bonding and the signs of aggression before attempting it.
https://www.cottontails-rescue.org.uk/information/bonding-bunnies/
http://www.saveabunny.org/rabbitcare/bonding-guide


It's important that you do your research and understand what signs of aggression(circling, tails up, flattened ears, tense upright position, etc) to look out for so that you can stop a fight before it begins(make sure to where protective clothing so you don't get bit) as fights can result in serious damage, they can even prove fatal to the rabbits in some instances.

It may be that because of previous tension between the two rabbits, that it may be necessary to take a break of complete separation before attempting bonding, for a few weeks to several weeks to give them time to forget one another and any bad feelings. Sometimes it's even necessary to put them in completely separate parts of the house with no contact for several weeks, before attempting bonding again.

 

[Sayuri Nakashima]

Thank you so much!!! I will definitely take this in consideration and try rebonding them again! Whenever we let them out, she starts chasing her with the intention of biting, so we were afraid to let them out together. We’ll try placing them in different parts of the houses, and rebond then. Thank you for the reply!