New research out of the UK has highlighted the importance of allowing pairs of pet rabbits the freedom to have exercise outside of their home enclosure.
Pet rabbits have higher levels of the stress hormone – corticosterone – and show activity rebound when kept in small hutches with restricted exercise, found the research led by the University of Bristol Vet School, and funded by the RSPCA.
The aim of the study, published in Applied Animal Behaviour Science, was to investigate the effects of common hutch sizes and access to an exercise area on the welfare of pet rabbits kept in pairs (which is advised by animal welfare organisations).
Twenty bonded pairs of adult neutered rabbits (one male, one female) were kept for eight weeks in standard housing. Ten pairs were in small wooden hutches (0.73sqm) and 10 in large hutches (1.86sqm). The exercise area was a run measuring 3 × 1m attached to the hutches, and the rabbits had either unlimited access to it, or access was restricted to three hours at midday.
Each pair had access to each run for three weeks and behaviour was observed at dawn, dusk and midday, and faecal samples were collected for corticosterone analysis at the end of each access period.
In a subsequent study, 10 of the rabbit pairs were given 24 hours access to the run, and their behaviour was recorded.
The study found that rabbit pairs were more active when run access was restricted to three hours. Irrespective of the hutch size, physical activity including play jumps increased significantly when the pairs with restricted access were released into the run. The researchers suggest this activity rebound demonstrates the rabbits’ need to move every day, and their welfare is compromised when they can only do so at midday.
It was determined that there is a significant interaction between hutch size and run access on activity and stress hormone levels, which were highest in the pairs kept in small hutches with restricted run access. When rabbits had unrestricted access to the run, midday was the rabbits’ least active time.
Drs Nicola Rooney and Suzanne Held, senior authors of the paper from the University of Bristol Veterinary School, said that rabbits are active and need to be able to hop, run, jump, dig and stretch out fully when lying down.
“Restricting rabbits’ opportunity to get away from each other and to move to times of day, when they would not naturally be as active, is likely to contribute to the activity peaks and high stress hormone levels in the pairs in the smaller hutches with limited access to a run.
“Housing guidelines for rabbits need to highlight the importance of allowing pet rabbits the freedom to exercise in the morning and afternoon, even if they are kept in hutches larger than the traditional hutch size.”
The study suggests hutch sizes of around a 0.75sqm floor area should not be recommended for rabbit pairs, even if they have access to an exercise area for three hours per day during the middle of the day.
The research’s recommendations have been incorporated in RSPCA and other animal charities rabbit care advice on housing.
RSPCA rabbit welfare expert Dr Jane Tyson welcomed the research findings, saying that they confirmed what many have long known, that keeping rabbits in small hutches with limited opportunities to exercise compromises their welfare.
“Rabbits are often misunderstood animals but the findings from the study show that housing rabbits in an enclosure consisting of a sheltered area with constant access to a larger space is critical.
“Not only does this allow rabbits to have more room for exercise, it provides them with choice and control over their environment so they can perform the behaviours they want to, when they want to.”