My rabbits have suddenly turned agressive.

[Stinkerbunnies]

So I have two male rabbits that I have had for over three years. We have a white and black lion head named Big Wig and a suspected Havana Lionhead named Blackie Chan. We got them from the same owner who had to give them up due to allergies. Apparently, they were close while they were little, but after they became adults, they of course started to fight over dominance. When we got them, they were probably 2-3 and we introduced them back to each other and they have been the best of friends ever since.

Now, maybe a month or so ago, Blackie Chan, who is the bigger of the two by about 1.5 lbs started to chase Big Wig around the cages in the early morning and the night time. We thought this was just him getting the zoomies out. Big Wig never reciprocated and would instead hop back and forth to the two cages just ignoring Chan. Then maybe two days ago, Chan did the same thing, however he started to mount Big Wig and actually tore out some of his fur. This was a shock because they will have little disputes over dominance every once and a while, but it never got aggressive. According to my sister, a week ago they were eating and Big Wig nipped near Chan's eye. Now today, I was petting Chan and Big Wig nipped the top of his head. This started another chase, again with mounting and bitting. I tried to put Chan low to the ground like I have seen other people do, and as soon as I raised my hand he was back at it again.

We think that they are both neutered and possibly from similar litters, so I don't see why this would be a problem and why they would suddenly start to fight now. We currently have them separated and they usually remain like that once they start fighting. If it has been a little bit and we think they have cooled down, we try to put them back together, but Chan will usually chase Big Wig around. They are usually fine when we bring them outside and don't fight. We got them the RHDV-2 vaccine over the summer, but I don't think that would have any difference. We are also cutting out most of their pellets and feeding them hay and greens, but this is not an astronomical change to their diet.

If you guys could please help me figure out what to do that and tricks to get them to stop, that would be very appreciated. Thank you!

 

[JBun]

Changes of their environment, changes in seasons, health issues, can all be a cause of sudden behavior changes in a bond.

The very first thing you need to do is check to make sure they are both in fact neutered. Intact males should not be kept together due to the likelihood of fighting occurring, even to the point of being fatal. If they aren't both neutered then that is the first step that needs to be taken, while keeping them completely separate until it is done and they are given at least 4-8 weeks for the hormones to fade before attempting to rebond.