Rabbits are a popular choice as a childs pet as they are percieved to be an easier option than a cat or dog. Their life expectancy is between 4 and 7 years and though they are generally low maintenance on a health front, there are some exceptions to this rule such as abscesses and dental disease that can cause ongoing difficulties. It is also important to understand their particular dietary and husbandry requirements.
In New Zealand most people that are considering a rabbit as a pet have a back yard with some grass. However increasingly there are more people switching to apartment living and as overseas we are starting to see some rabbits that are kept 100% inside.
Rabbits are herbivores with a fascinating gastrointestinal tract. Their natural diet consists of mostly grass and leaves, as well as occasional flowers and fruits. For this reason it is important that your rabbit has access to a constant supply of good quality grass hay as well as fresh grass. Rabbits teeth, both the incisors and the molars, grow continuously throughout life. A fibre based diet is important to ensure the teeth wear correctly and don’t become overgrown or develop sharp edges. Grass and hay are also important to provide “food” for the microorganisms in the gut and to stimulate healthy intestinal contraction. Chewing fibrous food also gives the rabbit a full feeling in the stomach, and can help prevent inappropriate chewing.
A good quality pellet is a good way to meet your rabbit’s nutritional requirements, however should only be fed in a small quantities, as they will not provide many of the benefits associated with hay and grass, and are likely to cause your rabbit to become overweight.
A unique adaptation of the rabbit gastrointestinal tract is the production of cecotrophs. These are a type of dropping that is eaten by the rabbit as soon as it is produced. These droppings are rich in organisms and breakdown products of digestion produced in the caecum/large intestine of the rabbit, this is close to the “end” of the intestine and past where the majority of nutrient absorbtion occurs. Eating these cecotrops gives the rabbits access to a variety of nutrients it would otherwise miss out on absorbing. As they are eaten straight away you will not usually see these droppings in the cage. they are elongated, greenish in colour, coated in mucous and have a strong odour – so they are quite different from “normal” droppings
What the ideal diet for your rabbit will be depends first of all whether it will be a predominately outside or inside rabbit.
If your rabbit lives outside with access to grass this provides a large part of the diet and can be provided by simply shifting the rabbit hutch from one area to another on a regular basis. The frequency of movement of the hutch will depend upon seasonal factors that affect grass growth.
This should also be supplemented with a constant supply of good quality hay. This hay should be stored in a clean and dry area until use. It cannot be overstated how important it is for your rabbit to chew – both from a behavioural angle – relief of boredom but also for keeping teeth in good health.
Rabbit’s teeth are different to cats and dogs being open rooted this means that they grow throughout the rabbits life. This new growth is worn down by chewing grass and hay. The main problem we see with rabbits and their teeth is that they over grow resulting in them cutting the roof of the mouth or damaging the lips or tongue. This can often have a genetic component but is often worsened by inappropriate feeding – too much pelleted food and not enough grass or hay
It is even more important to really carefully monitor these rabbits. Because they are inside we have taken away or dramatically reduced access to grass. This must be compensated for by collecting suitable greens – grass or similar from outside and also the provision of hay.
The temptation is to treat them like cats and dogs and to feed predominantly pelleted food – it is simple and easy however will be a health risk for your rabbit. These foods are concentrated and because the rabbit is inside it is often less active the a rabbit that is outside also environmentally has to cope with less change in temperature than a indoor rabbit. These factors make obesity more likely in the indoor rabbit this must be constantly monitored.
What is the answer for the indoor rabbit?
Firstly dietary – feed 75% of the rabbit’s diet in the form of hay.
Secondly exercise – where possible we would recommend the use of a harness plus lead and taking your rabbit to a local park to get some sunshine and also green grass to eat – alternatively you can use a collapsible pen that can be taken to the park and then the rabbit put inside. Obviously friends and family may also help out with this if they have a suitable back yard.
All rabbits require a healthy source of clean water. This can be provided with a sipper bottle or in a water bowl. Ensure the water bowl isn’t easy to knock over and make sure the water is changed daily..
Rabbits and rodents have a likeness to each other, but are assigned to different orders. Rabbits and hares belong to the Lagomorpha, whereas rats, mice and guinea pigs belong to the Rodentia. The difference is that the Lagomorpha have a second pair of incisor teeth in the upper jaw, in contrast to the Rodentia who only have one pair of incisors in the upper jaw.
Skin and scent marking glands
Female rabbits (= Does) have a large fold of skin over the throat known as a dewlap. Breeding females pull fur from this area to line their nests before kindling.
Rabbits don’t have footpads; rather, the feet are covered with coarse fur. Their claws are very sharp and a rabbit that is picked up without appropriate support of its hindquarters can inflict painful scratches.
Rabbits are strongly territorial and both sexes have three glands used in scent-marking behaviour, called the chin glands, the anal glands and the inguinal glands.
Males mark more frequently than do females, dominants of both sexes mark more frequently than subordinates and dominants mark most in the presence of subordinate rivals. They leave messages behind expressing their dominance. Under natural conditions, both bucks (= male rabbits) and does on their own territory, surrounded by their own odour and that of their clan, win two thirds of all aggressive encounters.
Does mark kits (= baby rabbits) with chin and inguinal gland secretions and they are openly hostile to young that are not their own. Kits smeared with odour from other rabbits are attacked and killed.
The skeleton of a rabbit is very delicate. Fractures are always a potential problem. Rabbits have powerful hind legs that can kick violently. If rabbits are not securely held when picked up, their kicking can result in a vertebral fracture and damage to the spinal cord.
The mouth opening in rabbits is small and the upper lip has a divided groove that continues by curving right and left to the nostrils- hence, the expression ‘harelip’.
Rabbits’ teeth are curved and the incisors and cheek teeth grow continuously. If the teeth are not aligned properly, they do not wear properly and rabbits present with malocclusion problems, such as trouble with taking food in or anorexia.
The abdominal cavity is large. The gastrointestinal tract is relatively long and the two most striking organs in terms of their size are the stomach and the caecum. Rabbits are unable to vomit because of the anatomic arrangement of the stomach.
The colon is characterised by the presence of bands and the colon contains a thickened section that has cells that act as little pacemakers for controlling the contractions for the excretion of the two types of faeces.
The fibre components get separated from the nonfibre components and the fibre rapidly moves through the colon for excretion in the hard faeces. The rest reverses into the caecum where it is retained for fermentation. At intervals, the caecum contracts and its fermentation contents are expelled through the colon and consumed directly from the anus by the rabbit. So, the products of bacterial growth are made available either by direct absorption or by consumption of the caecal contents. This latter process is known as coprophagy. The consumed faecal contents are called soft faeces/night faeces and they appear as a cluster rather than as single pellets typical of hard faeces. The soft faeces are surrounded by a mucous like membrane that acts as a barrier to the low pH of the stomach and that permits reabsorption in the small intestine.
Coprophagy is a source of B vitamins and a means of optimising the use of protein. If coprophagy is prevented, they lose weight, digest less fibre and excrete more minerals in the faeces.
Rabbits are obligate nose-breathers, so that means they are in pretty bad shape if they actually start breathing through their mouth.
In rabbits, the heart rate can vary from 180 to 250 beats per minute and their veins have very thin walls that are susceptible to haematoma formation.
Urine is a major route of excretion for calcium and varies directly with serum calcium concentration. The consistency of the urine is often thick and creamy because of a white, calcium carbonate precipitate. The colour of normal rabbit urine varies from yellow to red because it contains pigments. Certain type of feed, eg. Alfalfa, seem to increase the intensity of the pigmentation. This can be mistaken for blood in the urine.
Puberty and breeding life
Body weight is more important than age in determining sexual maturity. Small breeds develop more rapidly and are mature at 4-5 months of age. Medium-sized breeds mature at 4-6 months of age and large breeds reach maturity at 5-8 months of age. Does mature earlier than bucks.
The length of gestation in rabbits varies with the breed, but is approximately 30-33 days. Litter size depends on breed as well as on parity. First litters tend to be smaller than subsequent ones. Small breeds tend to produce small litters of 4-5 kits, whereas larger breeds produce large litters of 8-12 kits. The kits are born blind, helpless and hairless and remain in the nest for about 3 weeks. Does only nurse once a day for 3-5 min.In this brief period, the kit may drink 20% of its body weight.
Orphan rabbits can be fed kitten or puppy replacement formula, with egg yolk added to increase the fat content.
Eating and drinking behaviour
Wild rabbits are selective feeders with a wide food range. They prefer to eat tender, succulent plant parts as the major portion of their diet and consume small quantities of roughage, which are believed to stimulate gastrointestinal motility. Rabbits chew their food thoroughly. They are also adaptable to a high-roughage diet. They can consume a large volume of fibre because of the rapid digestive time. The primary feeding time for rabbits are in the early morning and at night, with coprophagy commencing 3-8 hours after eating. Rabbits like sweet materials and this preference can be used to our advantage when an anorexic rabbit is encouraged to eat, and medications can be given mixed with fruit jam.
Many pet owners feed their rabbits commercially available pelleted diets because they are convenient and balanced in their formulation. Do limit them though, otherwise they become obese and can develop chronic soft stools. Don’t let them just pick out the sweet or fatty parts either, otherwise the balance will be lost. Diet restriction in rabbits can lead to fur-pulling and destructive behaviour. This can be avoided through supplementation of the diet with fresh grass, hay and a variety of vegetables and by providing gnawing toys, such as a small log from an untreated fruit tree or sturdy plastic animal toys.
Rabbits can be kept indoors and outdoors. An indoor rabbit can either be caged most of the time and let out for supervised exercise or can be given free range. Still provide a cage or box for them to escape into, when frightened. Rabbits generally have clean habits, depositing their urine and faeces in the same place each time. They can be trained to use a litter tray, if they are constantly placed in the litter tray every few minutes when first acquired. However, adult bucks deposit strong-smelling faeces in scattered places to mark out their territory.
Two of the greatest hazards for rabbits in the house are electrical cords and poisonous plants. The decorative house plant dumbcane ( Dieffenbachia seguinea) and the ornamental shrub oleander (Nerium oleander) are poisonous for rabbits.
The base of the cage can be covered with a layer of straw or shavings that should be changed daily. If two or more pet rabbits are kept indoors, each animal should have its own separate cage, otherwise it can result in fighting.
Pet rabbits can be kept together in the same space with different pets, as long as the other animals adapt to the rabbits. Pet birds and well-behaved dogs tolerate rabbits well. Cats are often unpredictable. Pet guinea pigs are often kept in the same household as rabbits, but this is not a very good practice. Rabbits may carry an organism called Bordetella bronchiseptica without any ill effects; however, this organism can cause illness in guinea pigs.
Outdoor rabbits should be housed in properly constructed hutches that provide shade and shelter from wind and cold. Space to move around in the hutch is important and the space required for a rabbit to complete three hops, is the minimum recommended length. A fully grown New Zealand white rabbit moves forward 1.5-2 m in three hops. The hutch should also be tall enough for a rabbit to stand up on its hind legs.
Rabbits tolerate cold better than heat. Rabbits are unusually sensitive to elevated temperatures greater than 28 degrees Celsius and have little protection against high surrounding temperatures. They cannot sweat, except through sweat glands confined to the lips; also, they pant ineffectively. Rabbits do not increase water intake when the surrounding temperature becomes high; heat actually seems to inhibit drinking. Although rabbits use their ears as organs to dissipate heat, they actively seek shade and burrow to achieve water conservation and relief from heat. Shelter from direct sunlight is essential in the design of any rabbit housing.
Dietary fibre primarily stimulates gut motility rather than serving as a source of nutrition and is important in normal digestion.
The teeth of rabbits are developed for a high-fibre, herbivorous diet. They have 28 teeth, 16 in the top jaw and 12 in the lower jaw. Chewing is characterised by a side to side motion, which helps keeping the constantly growing teeth worn down properly.
Malocclusion secondary to an extension of the lower jaw, which can be a genetic trait, results in overgrown teeth. It often occurs with the incisors, but is also seen with the premolars and molars. This can then lead to sharp edges on the cheek side of the (pre) molars of the upper jaw and on the tongue side of the (pre)molars of the lower jaw.
The free-choice feeding of pellets often increases the incidence of overeating, obesity and diarrhoea, so it is preferred to provide a measured daily pellet intake, supplemented with hay and vegetables.
The most common clinical problems seen in rabbits involve the gastrointestinal tract. The environment and diet is very important. The rabbits who are allowed to roam the house are often exposed to a variety of potentially noxious food items and dangerous materials, such as electrical cords, carpet fibres and other foreign materials.
Often pet rabbits are fed an inappropriate diet for a herbivore, such as those foods high in simple sugars or high in protein and fat (eg dog or cat food)
For more information on rabbit care the veterinary partner rabbit care site is an excellent resource.