Rabbits need exercise
Well meaning but poorly informed people may describe rabbits as easy to keep because they can be caged and don't take up much space. This idea has led to many rabbits being caged most of their lives resulting in both physical and behavioural disorders.
The normal territory space of an adult European rabbit Oryctolagus cuniculus is about 2 acres but may be even larger if food is in short supply. This is the area over which the rabbit wanders each day to feed and look for mates. The rabbit requires large volumes of high fibre food and so travels great distances each day, particularly during winter months. In addition, rabbits are designed to be able to move at great speed in order to elude predators. They have powerful back legs built to run and leap.
It is not surprising that an animal designed to range over a large area, at times even at great speed, confined in a cage that is 24 x 24 x 18 for most or all of its life does not thrive and do well. Some people say that rabbits are happy in their cage, because in the wild they spend part of the day in extensive burrows underground and the cage represents that secure burrow space. But wild rabbits don't spend all day in the burrow, they need to exercise all their muscles, including the heart, strengthen their bones, burn fat and stimulate internal organ function which can scarcely be done when confined to a small space. In addition, caged rabbits develop behavioural problems due to the boredom of a small cage.
The argument that the domestic rabbit must be content in its cage because they reproduce successfully in small cages. However, the internal drive to reproduce is extremely strong in the rabbit because it is a prey animal and in the wild, many rabbits are eaten by other animals as part of the natural food cycle, therefore they must keep replacing their losses. If minimum requirements of food and shelter are met, the rabbit will reproduce if allowed to because he must!
But minimum requirements do not lead to a long, healthy life.
Problems caused by lack of exercise
Obesity is caused by a number of factors, but the 2 most common are too many calories for daily need and a lack of exercise. Just as in humans, if a rabbit sits around all day and moves just enough to take care of minimal daily requirements such as eating, defaecating and urinating, it isn't going to burn many calories, nor is it going to build muscle tissue. Obesity puts undue stress on the cardiovascular system, can result in pododermatitis (inflammation of the foot) as well as making the rabbit feel sluggish. Large folds of fat can develop around the rectal area or in the dewlap, which interferes with normal grooming and prevent eating of the nutrient-rich caecotrophes. If caecotrophes aren't eaten, the result can be serious nutritional deficiencies. An inability to groom properly can lead to a constantly soiled rectal area and subsequent skin disease. The cure for obesity is to keep your rabbit on a healthy diet of grass hay and fresh foods and avoid commercial pellets and high starch or sugar snacks.
Pododermatitis (sore hock) is a condition where the skin on the underside of the feet becomes inflamed resulting in ulcerations that can range from superficial to deep enough to involve bone. This condition can be caused by several factors, but the two most common are obesity and damp flooring. Wire cage floors can also make pododermatitis more likely, but this alone rarely causes a problem. In additions, there is a genetic disposition to this condition in breeds of rabbits, such as the Rex or Min Rex, where the fur on the underside of the foot is too thin to afford sufficient protection.
Obesity can contribute to foot disease because of the excessive weight being carried by the feet resulting in unusual wear on the footpads. In addition, if the rabbit is so fat that it can't clean itself, urine and stool can collect on the hindquarters and feet and result in skin disease.
A continually damp floor caused by urine or water in the cage or litter box (where rabbits often like to sit) is a contributing factor to the development of pododermatitis. If a rabbit is confined to a small cage it often has no choice but to site in a wet area. Urine, in particular, is very caustic and can result in serious burns and ulceration of the feet.
In the wild, rabbits are exposed to a wide variety of surfaces from hard packed ground or rocks to soft grass. It is important to provide some soft surfaces in addition to the normal wire or solid flooring. Squares of fake fur or fleece work well because they are absorbent, washable and non-toxic to the rabbit. Carpet squares are not ideal because they are not washable, and in some cases are more abrasive than the regular flooring. Use absorbent pelleted bedding in the litter box rather than kitty litter. Pelleted bedding pulls moisture away from the surface, which keeps the feet dry. In addition, pelleted bedding is non-toxic and comfortable. Cat litter is not only abrasive, but some rabbits will eat it and develop blockage in the gut which can kill.
Poor bone density
Animals that do not get sufficient exercise can develop osteoporosis (thinning of the bone). It is well known that in humans the best natural method to prevent this is to take regular exercise, caged rabbits often have serious bone thinning. Osteoporosis results in a spine or long bones that can break easily when the rabbit is handled, leaps off a high surface or runs or jumps rapidly.
Daily exercise is vital to the production of healthy bones.
Poor muscle tone
Obviously if a rabbit can't exercise, their muscles will be underdeveloped and weak. This can lead to an inability to move properly. The most important muscle is the heart. If the heart muscle is weak, the rabbit will be unable to tolerate stressful situations that occur, such as a child or curious puppy that chases the rabbit when it is let out to play. Rabbits in the wild do not ordinarily drop dead when being chased by a predator. They are superb athletes and can move rapidly, sometimes for great distances, to find shelter. This type of behaviour is part of their daily routine. However, if you take a rabbit that sits in a cage day after day and then let it out and force it to around the room rapidly it may faint or even die of heart failure. Therefore, exercise will help your rabbit develop a healthy cardiovascular system and be able to withstand inevitable stressful situations successfully.
Gastrointestinal and urinary function
A rabbit that sits all day in the cage with little exercise can develop abnormal elimination habits. Rabbits that exercise routinely will urinate and defaecate frequently which is good for the urinary and digestive systems. Holding urine or stool may contribute to a variety of conditions such as gut stasis and concentrated sludgy urine.
Behavioural problems in rabbits, as in other creatures, are complex. However, problems may resolve when rabbits are taken out of the caged environment and allowed more freedom. Stimulants such as toys and hiding areas also help. Continually caged rabbits can exhibit a wide range of abnormal behaviours including lethargy, aggression, continual chewing of the cage bars (sometimes leading to incisor damage), chewing fur (obsessive grooming), and destruction of the entire contents of the cage. These behaviours can also be seen in rabbits that are not caged, however, rabbits exhibiting these behaviours often improve in a more open environment.
An easy way to provide an open exercise area for your pet is to use dog exercise fencing that comes in panels that can be connected together in many shapes. These panels can be used indoors or out to provide a safe exercise area. In addition, you can place a large sheet of no-wax flooring under the pen to protect carpets and hardwood floors from being damaged by the rabbit's claws.