The warmer weather and the longer days of spring are a welcome relief for rabbit owners after winter. However, spring is also the trigger for rabbits to begin breeding, so for some owners, it can be the time of year their rabbits start showing challenging behaviours, potentially causing fallouts between bonded rabbits.
Seasonal breeders
Rabbits are seasonal breeders, which means they usually only reproduce at certain times of the year. For wild rabbits, they usually start breeding in spring when the longer day lengths trigger the hormonal changes required for breeding, resulting in mating behaviours being displayed. These behaviours are strong in rabbits, which means we can also see behaviours driven by hormonal changes in our non-breeding pet rabbits.
These hormonal changes do not only affect entire (un-neutered) pet rabbits, but on some occasions, they can also cause mating-type behaviours to be shown by neutered rabbits during springtime. Though usually, the behaviour changes in neutered rabbits are less severe compared to entire rabbits.
What does neutering mean?
Neutering (or desexing) is the term used when a rabbit has had their reproductive organs removed during an operation, so the rabbit cannot breed and have babies. For females, this may also be referred to as spaying and involves removing the ovaries and sometimes the uterus. For males, you may hear this called castration which involves removing the testes.
Along with preventing unwanted litters, neutered rabbits will also usually become calmer and less aggressive, making them easier to bond with other rabbits. Neutering can also benefit your rabbit’s health, as it prevents conditions such as testicular cancer in males and uterine disease and uterine cancer in females.
Hormones in neutered rabbits
After rabbits are neutered their reproductive hormone levels will drop over time. For males, the removal of the testes results in lower testosterone levels and for females, the removal of the ovaries results in lower levels of oestrogen. Generally, the lower levels of reproductive hormones present in neutered rabbits results in a reduction in mating behaviours and aggression, allowing neutered rabbits to be bonded together with less risk of fighting.
However, neutered rabbits still have low levels of reproductive hormones circulating, especially during spring when hormone levels naturally rise in entire rabbits getting ready to breed. During this time, neutered rabbits may show a recurrence of various mating behaviours, potentially causing fallouts or even fighting between bonded pairs or groups, otherwise known as spring fever.
Signs of spring fever
Rabbits with spring fever may show a number of different behavioural signs. These behaviours correspond with mating behaviours shown by breeding rabbits.
Signs of spring fever include:
Digging
Mounting behaviours
Increased episodes of chasing
Bonded pairs falling out with each other
Fighting – This can be severe, and can result in serious or even fatal injuries occurring if rabbits are not separated.
For many neutered rabbits, the signs of spring fever will be mild, so are manageable for owners without affecting a rabbit’s bond with their companion. However, for some rabbits, the signs of spring fever can be more severe, resulting in problems developing between bonded rabbits with the potential risk of injury occurring.
Not every rabbit will show signs of spring fever, but it is worth keeping a closer watch on your rabbits during the spring and summer months in case behaviour changes occur. If you notice that your rabbit’s behaviour has changed, especially if this coincides with spring, they will need to be monitored for any signs of fighting. It is not usually necessary to separate bonded rabbits that are both neutered, unless fighting occurs when rabbits will need to be separated to prevent any serious injuries.
How to help rabbits through spring
There are several steps that owners can take to help keep their rabbits settled during spring including:
Increasing foraging opportunities – Try hiding your rabbits dried food within the hay.
Provide your rabbits with plenty of toys and mental stimulation – Rabbits love cardboard toys such as egg boxes or cardboard rolls filled with hay, and many also enjoy trays filled with soil or hay where they can dig.
Make sure your rabbits have plenty of space for exercise, ideally with permanent access to a run – This also ensures rabbits can get away if they are chased by their companion. Rabbits also enjoy hiding in tunnels and boxes, which are also great for increasing mental stimulation.
Offer increased numbers of resources – Make sure there are more litter trays, water bowls/bottles and feeding areas than the number of rabbits in the group. This ensures all rabbits can access their vital resources while being able to avoid any rabbits they may not be getting along with.
If possible, avoid bonding any new rabbits together during spring – The higher hormone levels circulating during spring can make the bonding process longer and harder to achieve.
Try not to separate bonded rabbits – Rabbits should only need to be separated if they are fighting or if there is a risk of any injuries occurring. If you notice any wounds or injuries, you will need to take your rabbit to see your vet as treatment may be needed.
Spring fever can affect any pet rabbit, so owners should closely monitor their bonded rabbits during spring and the warmer months. If you notice any difficult to manage behaviour changes or find any injuries to your rabbit, speak to your vet for advice.
Written By Lisa Butwell – Veterinary surgeon and bunny mum.
