Desexed male aggressively mounting his bonded female

[krista64]

My 8 year old male , who has been desexed for 7 years, has suddenly started aggressively mounting my desexed female. They are a bonded pair and have been together for 1 and a half years. He has not shown this behaviour before. Nothing in their environment has changed. We have tried separating them , where they can still see and smell each other. This has had no impact. As soon as we put them back together his mounting behaviour returns. I know desexed males still have some testosterone in their system and it is Spring here in Australia but I'm concerned as this has been going on for about a month.
Any advice, tips, similar stories would be greatly appreciated.
Thanks

 

[JBun]

It could be spring fever, though after a month I would have expected it to settle down. Another possibility given his age and if the behavior doesn't settle down, is that he is developing adrenal problems. This can cause abnormal excessive hormonal behavior in a spayed/neutered rabbit that had previously not shown this behavior. A blood test would be needed to determine if this is what is going on.
https://rabbit.org/journal/4-10/sexhormones.html
https://rabbit.org/vet-listings/

 

[krista64]

Thank you so much for your reply, it was very informative, we'll book him straight into the vet for tests.