Sexual Behaviour in Desexed Rabbits
Behavioural changes in rabbits can arise from a variety of medical and psychological causes. It is important to robustly investigate these cases in order to provide specific treatment. In neutered animals a return to sexual behaviour may arise from inadequate surgical neutering, or production of sexual hormones from another source such as ectopic or accessory gonadal tissue or the adrenal gland. It is suggested that adrenal hyperplasia or neoplasia be considered a potential cause of sexual behaviour in neutered male rabbits.
Hypersexuality in a castrated rabbit (Oryctolagus cuniculus) - Molly Varga BVetMed DZooMed MRCVS
Not all sex hormones are produced by the ovaries and testes, so when we remove these, the adrenal gland will continue to produce some. Although the rabbit cannot produce sperm or egg cells, the adrenal gland can still produce some sex hormones – especially during the spring. Some rabbits will show more sexual behaviours than others – this seems to be because some adrenal glands produce more testosterone than others, and in some rabbits, the adrenal glands may increase production of testosterone when the testes are removed. Neutered rabbits have higher levels of sex hormones than neutered animals of other species (like ferrets, cats, and horses) – this would indicate that the adrenal gland produces a fairly substantial amount of sex hormones (House Rabbit Society, 2004).