Housing and husbandry: Rabbit

Good housing and husbandry for rabbit housing should take account of the following principles:

• Housing in pens on the floor should always be considered before cage housing. Where cage housing is used an elevated platform should be provided.
• Pens should be large enough for animals to hop, jump and make quick changes of direction.
• Pens should have sufficient height for rearing upwards for scanning, exploration and play.
• Floors should be solid with substrate (2 to 5cm in depth) for hygiene, comfort and to permit foraging and digging behaviour.
• There should be sufficient space for group housing, exercise and inclusion of essential enrichment that facilitates the animals to perform a wide range of normal behaviours.
• Rabbits should be housed in stable, compatible groups, established with immature animals of the same age and sex, as soon as possible after weaning.
• Entire male rabbits should be separated from other males at sexual maturity (12 to 14 weeks) and housed individually with visual and olfactory contact with other rabbits. 
• For longer-term studies, males should be castrated to allow for social housing.
• Breeding females should be provided with nest boxes containing nesting material, that are designed so that littering does cannot see each other to minimise the risk of infanticide.
• Rabbits should have a raised area to make use of the vertical space, offer a comfortable resting place and refuge, stimulate exercise and offer a choice of microenvironment.
• Hay should be provided for foraging, play, nest building, and for a varied diet.
• Rabbits should always have access to something to gnaw (e.g. wooden blocks) for enrichment, chin-marking and to prevent the teeth from overgrowing.
• Visual barriers should be provided to allow the animals to initiate or avoid social contact. 
• Rabbits should have access to substitute burrows (e.g. plastic crates, sections of appropriately sized PVC pipe) for retreat in fear-provoking situations and to manage social interactions.
• There should be good visibility out of the pen (e.g. mesh or plastic wall) so that the animals can overlook their surroundings and see approaching personnel.
• Rabbits should experience gentle and frequent handling from early in life.
• Rabbits should be habituated to procedures, particularly when they are used for repeated sampling.
• Health monitoring in the rabbit unit should be in accordance with the Federation of European Laboratory Animal Science Associations (FELASA) guidelines.

Rabbits used in laboratories descend from the European wild rabbit (Oryctolagus cuniculus) [1,2] Their behaviour has not changed significantly through domestication; New Zealand White rabbits kept in a near-to-nature environment show the same behaviour as their wild relatives [3].

Wild rabbits live in social groups consisting of one to four males and one to nine females. The group defends a central warren but can come together with other groups while grazing when they feed in an area known as their home-range which can be up to 50,000 m² [4,5]. The females construct nests in which the young are born, and the nests are visited once daily for a few minutes to feed the young. After about three weeks the young come out from the nests and they are weaned a week later [3]. Most of the time above ground is spent feeding and they mostly consume grass and herbs [5]. They need coarse fibres for their digestion and it is critical to maintain their intestinal flora [5].

Rabbits are often described as nocturnal, however, as the activity of wild peaks during dawn and dusk, crepuscular is the more accurate term [6,7]. Within a research environment rabbits can adapt to a diurnal schedule [8].

In the group there are two separate social hierarchies, one among males and another among females [3]. The males occupy territories which they defend from one another while the females stay in a specific area but will not defend it against other rabbits [3,4,9,10]. Rabbits have a number of scent glands located under the chin and in the anal and groin regions. They mark their territory with their faeces or by rubbing their chins-against objects [6].

Confinement within small enclosures has negative effects on rabbit welfare, both in terms of psychological stress and physiological health [11,12]. Housing in larger, enriched enclosures is associated with behavioural indicators of higher welfare [8,13,14].

Rabbits are a naturally gregarious species and single housing can causes significant welfare issues [8,15,16]. As with any species, care and consideration should be taken when pair or group housing rabbits and a well-structured plans for monitoring and maintaining welfare are essential [17,18].

See the Managing aggression in laboratory animal species webinar for more information, species specific information for rabbits begins at 15:33.

The separation of rabbits from conspecifics in a barren environment prevents them from performing natural behaviours such as digging, allo-grooming and some locomotory activities. It also reduces their exposure to variations in odours and diet [7]. This can lead to the development of abnormal behaviours, for example, excessive wall-pawing or bar-gnawing [7,9,16,19]. Stereotypic behaviour seems to be most frequent at night when rabbits are most active [7]. Rabbits that are more active tend to become more frustrated and show more abnormal behaviours [7]. Social isolation has been shown to induce physiological signs of stress [6] and individually caged rabbits can also show signs of restlessness [20] and boredom [7,20]. They also develop intestinal disorders [7] and the limited freedom of movement has been shown to give changes in muscles, bones and joints [4,7,13].

Rabbits should wherever possible be kept in social groups in pens to meet their need for social behaviour and exercise [8,15,16,18;20-24]. Females can be kept in groups in pens and breeding females in groups with a male [24]. Rabbits in groups are more active and show fewer stereotypies than those kept in cages [15,16]. They also express a broader behavioural repertoire. When rabbits are kept in groups their quality of life significantly improves even though they may experience from time to time social stress [22,25].

Where single housing is deemed necessary animals should be provided with adequate environmental enrichment and visual and olfactory contact with conspecifics.

For group housing, it is important to consider the compatibility of individual animals; when incompatible rabbits are housed together they will fight and this is especially problematic with males [18]. When males are going to be used for longer studies, castration is a good option as castrated males function well in group housing.

Continuous monitoring of groups is necessary as factors such as life stage, reproductive status and hierarchical position can influence preference for social interaction and group stability [17,27]. Group housed rabbits should be provided with enough space and environmental complexity to manage their interactions with their group mates.

Environmental enrichment is essential for the psychological and physiological wellbeing of rabbits. Creation and maintenance of suitably hygienic, enriched spaces for rabbits is achievable in a research setting [11,26,29].

Suitable enrichment includes straw, hay, chew sticks, cardboard boxes, raised areas and background noise (e.g. music) and taking the rabbits out of the cage for handling or exercise [19,22,28,29]. 

The inclusion of mirrors within the enclosure can improve the welfare of rabbits [31-33]. However, the evaluation of mirrors as enrichment is necessary and should involve careful monitoring of individual responses, as mirrors may have a detrimental effect on some rabbits [33].

Where cages are used, a raised area or shelf should be provided as it reduces abnormal behaviours and nervous responses when animals are captured [6]. It adds structure to the cage and allows the rabbits to move in a way so as to maintain normal function and the structure of muscles, bones and joints [25]. The shelf provides a darker area which can be used when disturbed [25] and functions as an important hiding place from intense light, which can cause retinal damage in albino animals [6]. Taking individually housed male rabbits out of the cage and letting them run in a floor pen with different objects can also be an enrichment, as they are given a change of environment, odors from other male rabbits which stimulate scent marking, and opportunity to move over a larger area, which can help to reduce obesity [19,29].

Rabbits are susceptible to different diseases and should be purchased from breeders using barrier breeding systems [6]. Rabbits from sources other than a barrier system or wild caught rabbits should never be mixed with the barrier bred rabbits. When introducing rabbits from another colony, quarantine should be used as a precaution [6]. FELASA has developed recommendations for health monitoring laboratory animals in different situations, and have published an updated recommendation concerning rodents and rabbit colonies in breeding and experimental units [34].

Rabbits should be habituated to handling with frequent, gentle contact from a young age. This training video from ACT online training outlines key considerations for handling rabbits.

The following videos show the traditional techniques for how to lift a rabbit and how to restrain a rabbit. Note that the while the scruff of the neck may be used to secure a rabbit, they should not be lifted by the scruff and should always have their weight fully supported from below. 

The handling and restraint of rabbits should be refined using positive reinforcement training. For example, rabbits can be trained to hop directly from their enclosure into a transport box, removing the need for capture and manual restraint in some circumstances.

• Thurston S and Ottesen JL (2020). The Rabbit. In: Animal-centric Care and Management, 1st edition. CRC Press.
• Oxley et al. (2018). A survey of rabbit handling methods within the United Kingdom and the Republic of Ireland. Journal of Applied Animal Welfare Science 22(3), 207-218. doi: 10.1080/10888705.2018.1459192
• ACT online training (2017). How to pick up rabbits. 
• Bradbury and Dickens (2016). Appropriate handling of pet rabbits: a literature review. Journal of Small Animal Practice. 57(10), 503-509. doi: 10.1111/jsap.12549
• Lofgren J (2015). Rabbits. In: Comfortable quarters for rabbits in research institutions. 10th edition. Animal Welfare Institute.
• Turner PV (2014). Rodent And Rabbit Welfare In The Research Environment. In: Laboratory Animal Welfare. Academic Press.
• RSPCA/UFAW (2008) Refining rabbit care - A resource for those working with rabbits in research.