Rabbits

1. Rabbits

2. Rabbit biology • Lagomorph (‘hairy ears’) • originally classified as rodents but have 6 incisors and rodents have only 4 • Oryctolaguscuniculus • Lifespan 6-12 years • Adult weight 900-6000g • Breeds - New Zealand White, Dutch • Originate from Asia and southern Europe – arrived in UK with the Normans? • Open rooted teeth • Grow 2-2.4mm/week

3. Rabbits in the wild • Mixed groups of 2-10, defend territories about 50m in diameter. • Social group size changes depending on the season. • Winter: small social groups • Summer: large warren with several groups. • Warrens used for breeding – several males defending against predators is essential • Group territories do not usually overlap unless territory marking is inadequate. • Individual rabbits have overlapping home ranges within whole • Males have larger home ranges than females • Habitats chosen based on the amount of food and predator protection • Rabbits graze near their burrows and can overgraze leading to permanent damage • Birds of prey are their main predators, but also carnivores

4. Rabbit behaviour • European rabbits are nocturnal and territorial • Mark territory with faeces, urine, glandular secretions from chin gland wiped onto objects (chinning) • Most social interaction occurs underground, avoid one another above ground • Territoriality and aggression are common during maturation: innate behaviours, help ensure survival of the population • During maturation, males and females become better at fighting off predators and protecting their territory • European rabbits are born into their social group. Offspring disband at the end of breeding season, and subordinate adults venture into different warrens, ensuring gene flow and avoiding inbreeding

5. Communication • The main mode of communication is olfactory • Mark territory with odour from their submandibular (chin) gland, urine and anal glands. • Patrol their territories during the breeding season, and mark them with dung hills (large faecal pellets covered with secretion from the anal gland). Both sexes regularly visit these latrine sites: • Males visit more frequently than females • Females spend more time grooming and resting • Territory marking is extremely crucial for rabbits: if the breeding territory is not clearly marked, outbreeding can occur. • Heightened defence of the territory is seen during breeding.

6. Rabbit nutrition • Obligate herbivores • Rabbits have evolved to eat a low quality, high fibre diet (12-22%) • Lack of fibre is detrimental • The main site for digestion is the caecum – microbial fermentation • Coprophagy is essential • soft faeces passed at night (caecotrophs) and ingested directly from anus • Excess readily digestible carbohydrate is detrimental • disruption of the microbial flora in the caecum • diarrhoea, fur chewing and hairballs • Overeating may be a stereotypy: ad lib feeding may result in obesity • Provide environmental enrichment and a variety of foodstuffs • Hay is important

7. To avoid digestive disturbances • Feed good quality roughage - fibre increases bulk and reduces the incidence of hairballs • Avoid excess highly digestible carbohydrate • Changes in diet should be gradual to avoid diarrhoea

8. Puberty (days) Age to breed (months) Gestation (days) Litter size Birth weight (grams) Weaning age (weeks) Oestrous cycle (days) 90-120 (f<m, dwarf<large) F 4-9 M 6-12 31-33 4-10 30-70 4-8 Induced ovulator Receptive 7-10d then not 1-2d Rabbit breeding

9. Rabbit breeding • Induced ovulator – mating results in pregnancy in 75% • Does line nest with fur • Does kitten very quickly – 10 minutes! • Kits are immature: blind, hairless • They remain in the nest for 14-18 days • Doe feeds kits only once daily for 2-3 minutes, but kits can drink up to 25% bodyweight in that time! • Start eating solid food from about 3 weeks • Once they are old enough to leave the nest, they stay in the core area of the territory for better defence

11. Dispersal of the young • When young approach maturity, they may disperse from their natal group. This depends on age, sex, inbreeding, fitness ability, inter-specific competition, amount of predation, and environmental conditions • Males compete with other males for females. Those that are too young or subdominant are forced to find a new territory • Inbreeding also drives dispersal: females look for high ranking males with a low degree of relatedness to enhance reproductive success • Natal dispersal allows rabbits to find new territory with the potential for higher quality resources and mates. Rabbits are not forced out of their natal units due to aggression, but simply choose to leave • Males moving farther away, whereas females moving into neighbouring territory • Rabbits that disperse do so before they are fully mature, at around 8 months for males and 5-8 months for females

12. Rabbits in the laboratory • Rabbits are social animals. Group house in floor pens or pair house in large cages • Male rabbits can be very aggressive – may need single housing • Environmental enrichment to provide shelter and ‘bolt holes’ • Communicate through behaviour and pheromones • Ear position, thumping, latrines, ‘chinning’ • Sufficient space to perform natural behaviours • territory marking (chinning) • exploratory and tunnelling behaviour • social activity and aggression. • Need to exercise to avoid cage paralysis • Enough height to stand and ledges to climb on

14. Anaesthesia • Stress and general anaesthesia can lead to cardiac and respiratory arrest • pre and post operative stress kept to the absolute minimum • Premedication prior to induction of anaesthesia is advised to reduce anxiety • Inhaled agents should not be used for induction • Stressful, leads to breath holding and apnoea • Induce anaesthesia with an injectable agent • Inhalational agents for maintenance. • Endotracheal intubation is recommended • Rabbits are prone to GIT stasis and inappetanceafter GA, and may need supplementary feeding or gut motility stimulants

15. Minor procedures • Blood collection • Marginal ear vein • Use local anaesthetic cream • Insert over the needle cannula • Central ear artery • Apply pressure after removing needle • Administration of substances • Oral – food or water • Intravenous – marginal ear vein • Subcutaneous – scruff of neck • Intramuscular – thigh muscles • http://www.ahwla.org.uk/site/tutorials/BVA/BVA08-Rabbit/Rabbit.html

16. Humane killing • Schedule 1 methods: young and adult • Overdose of anaesthetic • Dislocation of the neck – under 1kg • Concussion – under 1kg • Schedule 1 methods – fetuses • Overdose of anaesthetic • Decapitation <50g • Cooling and immersion in fixative • Confirm death before disposal of carcase

17. Rabbit diseases • Viral diseases: • myxomatosis, viral haemorrhagic disease of rabbits • Encephalitozoon: • protozoan. Very common. Neurological, renal, or ocular signs, or nothing. Significance? • Bacterial infections: Pasteurellamultocida • Subclinical. Exacerbated by stress. Signs - sudden death to snuffles • Diarrhoea. Multiple causes, including diet changes and inadequate fibre (less than 15%) • Inappetance. Environment or diet changes, hairballs, or subclinical diseases. • Many of the commonest diseases of rabbits are husbandry related

18. Recognition of PSD and LH • Rabbits • Stoic – signs of pain and distress may be subtle • Reduced food and water intake • Limited movement • Isolation • Photosensitivity and ocular discharge with protrusion of the third eyelid • Faecal staining of the coat, digestive disturbances, and dehydration • Twitch and writhe like rats, but very slowly • Rabbits may press their ears back when alarmed

19. Rabbits - summary • Lagomorphs originating from southern Europe and Asia • Need a high fibre diet – hay for fibre and enrichment • Social animals with complex natural behaviour – group house compatible animals • Need room for adequate exercise to avoid cage paralysis • Induced ovulators – breed like rabbits! • Many diseases are husbandry related • Stoic – hard to spot when ill

20. Options • Take the self-test quiz • Go to further resources • End show

21. Further reading • Hubrecht R and Kirkwood J (2010).UFAW Handbook on care and management of laboratory and other research animals, 8th Edition, chapter 28 • Wolfensohn S and Lloyd M (2013). Handbook of laboratory animal management and welfare, 4th edition, chapter 11 • Self test quiz • End show