Category: miscellaneous-health-problems-rabbits

Muscular dystrophy and other muscular conditions

Generalised muscle weakness in rabbits has numerous causes, many of which are extremely rare or have never been conclusively diagnosed in rabbits, but are important to discuss. By its definition, muscular dystrophy is defined as a degeneration of muscular tissue sometimes caused by faulty nutrition. This has been seen to occur in rabbits as well as other mammals.

Muscular dystrophy is a broad term that is used to describe a group of inherited diseases that are categorised by a progressive weakness and degeneration of the skeletal muscles (paresis). As the disease progresses and the muscle fibres weaken, fibrous and fatty tissues replace them. The disease is caused by a gene mutation that is transmitted genetically from parents to off-spring.

The main cause of muscular dystrophy in rabbits is a serious lack of, or no, vitamin E in the diet, leading to a deficiency. Clinical symptoms include mortality of neonates during the first 3-10 weeks of age, weakness, coma and eventually death.

Currently there is no cure for muscular dystrophy, nor is there any way of slowing the progression of the disease. Medical management may include supportive treatment, pain management, a good diet and respiratory support. Steroids may be of some benefit, but the potential side-effects need to be taken into consideration.

Floppy rabbit syndrome

Floppy rabbit syndrome (FRS) has been well documented in rabbits but its exact cause has never been truly identified. Rabbits affected with FRS lose all the strength in their limbs, but remain bright and able to eat and drink as long as food is put within reach. Lead poisoning, hypokalaemia (potassium deficiency) and plant toxins have all been cited as potential causes, although no diagnosis based on investigative evidence, has ever been documented.

Often after 2-3 days, with supportive treatment, rabbits seem to spontaneously self-cure of FRS; however some may relapse some weeks, months or years later.

Myasthenia gravis (MG)

An extremely rare autoimmune disease that causes muscle weakness and excessive muscle fatigue. This varies in severity affecting voluntary muscles in the legs, neck, eyes, respiration, etc. Smooth muscles and that of the heart (cardiac muscles) remain unaffected.

Treatment normally consists of anti-cholinesterase medication (pyridostigmine), which prevents the breakdown of acetylcholine and improves the chemical signal at the neuromuscular junction.

Immunosuppression in the form of steroids can also be used to suppress the immune system, however, steroids can have side-effects, so should be used with caution. Due to the side-effects, often additional drugs are used, such as azathioprine or ciclosporin. These also suppress the immune system and allow a lower dose of steroids to be given.

MG is often diagnosed by clinical symptoms and a response to treatment, but can be diagnosed with the Tensilon® test, whereby an injection of edrophonium is given, which results in rapid, but short-lived improvement in the symptoms.

Prognosis is guarded to poor, since the condition cannot be cured and the risk of inhalation pneumonia from choking on food is high. Rabbits diagnosed with MG are normally euthanased.

Hepatic lipidosis

Any length of time without constant throughput of food within the gastrointestinal tract can begin a sequence of events that can prove to be rapidly fatal to the rabbit.

Rabbits who go any length of time without food become hypoglycaemic (low blood glucose), which stimulates the mobilisation of fatty acids from the fat reserves. These are transported to the rabbits liver, which are intended to be used as an energy source. The fat accumulates in the hepatocytes (liver cells), leading to liver failure and death, sometimes within a few hours. Symptoms of hepatic lipidosis can include muscle weakness.

Pregnancy toxaemia

Pregnancy toxaemia is a disease that may affect rabbits during late gestation and is characterised by abnormally low levels of sugar and high levels of ketones in the blood.

Predisposing factors are generally obesity and anorexia. The main clinical signs are generalised weakness and incoordination. The rabbit is generally very quiet and unwilling to move. In severe cases, if not treated as an emergency, it can lead to death.

Treatment consists of administration of glucose solution, fluid therapy and assisted feeding.

Encephalitozoon cuniculi (E. cuniculi)

E. cuniculi has been documented as occurring in up to 50% of rabbits; many of whom carry the parasite asymptomatically and remain healthy throughout life and never suffer from any of the symptoms related to the parasite.

However, symptoms can include paresis, including paralysis of the limbs. Other symptoms may include head tilt, urinary incontinence, rolling, nystagmus (rapid flicking of the eyes), uveitis, fitting or even sudden death.

Treatment is aimed at reducing the inflammation within the brain and kidneys, which the parasite has caused and returning the parasite back to its dormant stage. This is usually achieved with medication such as fenbendazole for at least 28 consecutive days. Sometimes a longer or repeated course is required. Supportive treatment is aimed at maintaining gastrointestinal function, pain relief and the mental and physical wellbeing of the rabbit, until the rabbit is capable of supporting itself.

Despite intensive treatment, sometimes some rabbits do not respond to treatment and require euthanasia to spare them suffering any further.

Feeding a good diet that is contains adequate amounts of vitamin E is essential; all good quality rabbit foods will contain sufficient amounts of vitamin E.

Rabbits can be blood tested to see if they are positive for E. cuniculi. However, a positive result does not indicate an active infection. It only indicates that the rabbit has, at some point in their life, been exposed to the parasite. A negative result is evidence that the rabbit is clear of E. cuniculi.

Ensure that if your rabbit stops eating, you contact your vet as soon as possible. Hepatic lipidosis and pregnancy toxaemia can begin after only a few hours of anorexia. Obesity should also be addressed and treated.

Hip luxation

Luxation (dislocation) is defined as ‘dislocation of a joint so that there is no contact between the articular surfaces’. Rabbits have very delicate skeletons, and as their muscle mass is large relative to their skeleton injuries to joints can easily be caused through trauma or abnormal or excessive sudden movements. In addition, congenital abnormalities are also seen in rabbits and therefore hip luxation may be commonly encountered in pet rabbits.

Luxation of the hip is when the ball of the hip joint comes out of the socket, instead of normally sitting nicely in contact with each other. This is often caused by trauma, which may be as little as the rabbit jumping and landing awkwardly, or any forceful trauma to the hip, e.g. being trodden on, running into something, fighting, kicking out when being picked up, etc.

Clinical signs after trauma are often immediate with the rabbit having an obvious limp and looking very uncomfortable on the affected limb.

Congenital conditions causing luxation may appear more slowly as the rabbit develops.

Splay leg is a term often used to describe a number of developmental conditions in young rabbits of up to a few months old. The affected rabbit is unable to adduct the affected limb/s, i.e. hold it in the normal position under the body, and often has an appearance much like Thumper in the film Bambi, where he slides on the ice! The condition can affect forelimbs as well as hindlimbs, but seems more common in the hindlimbs.

Euthanasia is often the kindest option for those rabbits that have more than one limb affected. Those affected to a lesser degree may be able to cope with careful management of their environment, ensuring they are kept clean and are housed on non-slip flooring.

Since the condition is inherited, affected rabbits should never be bred from.

Diagnosis of luxations can be performed by taking an x-ray of the rabbit’s hips and pelvis. Often two views are needed, a lateral view from the side, and a ventrodorsal view achieved by lying the rabbit on their back.

Rabbits are often sedated or anaesthetised for this, since in order to achieve diagnostic images, the rabbit needs to remain totally immobile.

Sometimes it is possible to put the luxated hip back into its socket by manual manipulation, which must be done under sedation or anaesthesia since it can be painful to the rabbit.

It is sometimes necessary to perform corrective surgery, as often the hip can re-luxate within hours, days or even weeks after being placed back into the socket, and therefore permanent stabilisation is required.

Eye abscesses

Abscesses develop when bacteria enter a part of the body. It is the body’s natural defences to try and ‘wall off’ infection to stop it spreading elsewhere within the body. This can lead to problems when the abscess is located within the region of the eye, since the location is hard to successfully operate on, and the case is frequently difficult to cure.

Abscesses are a common occurrence in rabbits, and form when bacteria enter the skin or a body cavity, and sets up an infection. This causes a pocket of infection to form, characterised by an accumulation of pus.

Unlike dog and cat pus (exudate), rabbit exudate is thick and semi-solid, much like toothpaste, making it difficult to flush. This causes a high recurrence rate, since only a small amount of exudate needs to be left inside the abscess cavity for it to return.

Abscesses that are located around the face are often due to dental disease, which can also manifest as ocular problems, since the upper tooth roots can overgrow and impinge upon the eye socket and the nasolacrimal tear duct.

Abscesses that develop behind the eye are known as retrobulbar abscesses. They are very well encapsulated and because of their location they are very difficult to reach and drain.

Dental disease is often a predisposing factor since the roots of the upper cheek teeth can impinge upon the eyeball, and in extreme cases penetrate through it. The food passes from the mouth to the socket of the root developing infection that eventually becomes an abscess.

The most common signs of a retrobulbar abscess are bulging of the eye, protrusion of the third eyelid across the eye and inability to close the eyelids completely. Abnormal ocular or oculonasal discharge can also develop as a consequence of the eye irritation and the rabbit may show signs of discomfort such as excessive blinking and grinding teeth.

In chronic cases, rabbits can continue eating and drinking normally, but often the rabbit will deteriorate as the pain escalates or the dental disease progresses and eventually will stop eating and passing faecal pellets.

There are many investigations that are possible to perform in order to make a diagnosis of retrobulbar abscess; the first is the a physical examination. Often, in moderate to severe cases, it is possible to make a presumptive diagnosis after having examined the affected eye and the mouth for the presence of dental disease.

However, in order to confirm the diagnosis, radiographic and ultrasonographic examinations are generally the tests of choice. Radiography (x-rays) of the skull is generally performed under general anaesthesia. X-rays will not only show abnormalities behind the eye, but will also give the opportunity to confirm or rule out dental disease.

Ultrasonography (scan) of the eye can be performed when the animal is conscious or under light sedation depending on the nature of the animal. However, this test is limited to the evaluation of the eye and the retrobulbar space.

Ideally a computed tomography (CT) or magnetic resonance imaging (MRI) scan should be taken to assess the extent of the abscess, the infection and the tooth roots, but often this is not possible due to financial constraints.

It is also posssible to aspirate material from the abscess and test it for bacteria in order to make a diagnosis of infection rather than tumour, and also to choose the best antibiotics as treatment.

Unfortunately, retrobulbar abscesses are very difficult to treat due to the thick exudate that is difficult to drain and due to the location just behind the eye.

Medical treatment is generally unrewarding and surgical removal of the eye (enucleation) is usually necessary. Surgery allows complete removal of the abscess and a thorough flushing of the cavity to ensure that none of the exudate is left within it. The abscess cavity may also need debriding and being packed with antibiotic impregnated beads.

Occasionally this can be curative, but since the origin of the problem is very often related to dental disease, this will also need to be addressed. This can prove long and expensive, and treatment may need to be aimed at palliative care, to keep the rabbit comfortable for as long as possible.

Drainage of a retrobulbar abscess through the mouth can be successful in mild cases, and if caused by a tooth. In this case, the tooth needs to be removed as well as long-term medical treatment with antibiotics started.

Treatment of retrobulbar abscesses is an extremely difficult procedure and, unfortunately the majority of chronic retrobulbar abscesses may recur.


Arthritis is a well-known, documented condition affecting humans, cats and dogs. R rabbits can often be affected too, especially as they get older, and sometimes this can go un-noticed.

Arthritis is a general term given to the inflammation of a joint or joints, and any joint within the body can be affected. Arthritis isn’t a single disease, but rather a group of abnormalities that can have different causes, all of which lead to inflammation of the joints. Arthritis is a progressive condition and can cause significant pain and discomfort.

Arthritis can occur naturally as your rabbit ages; however rabbits are particularly susceptible to arthritis if the joints are put under extra strain, i.e. large breeds of rabbit, fat/obese rabbits or those with missing limbs. These extra stresses cause the joints to wear more quickly than they would do under normal circumstances. Arthritis due to injury of the joint earlier in life is also common. These conditions are commonly referred to as osteoarthritis.

Other causes include bacterial infections causing septic arthritis. This can be caused by penetrating injuries where bacteria are introduced to the joint capsule leading to inflammation. This type of arthritis can occur at any age and in any breed of rabbit. If a rabbit contracts an infection, as a results of trauma, dental disease or upper respiratory tract infection, there might be an increased risk of bacteria migrating to the joint, causing septic arthritis.

Rheumatoid arthritisis another type of arthritis caused by an over-reaction of the immune system; the immune system mistakes the body’s own protein for bacteria and attacks it leading to inflammation within the joints. Rheumatoid arthritis does not seem to occur spontaneously in domestic rabbits.

As your rabbit ages, you may notice your rabbit slowing down and isnt as active as it used to be. This can be a normal sign of aging, and may creep up very slowly, making recognising and diagnosing arthritis quite difficult on clinical signs alone.

You may notice that your rabbit has difficulty getting in and out of the litter tray, getting up or hopping around. Your rabbit may struggle to move around, present an abnormal gait or have difficulty grooming, leading to an unkempt coat or a mucky bottom. Your rabbit may not be able to scratch its ears, so excess amounts of earwax may accumulate. Urine scalding may develop in some cases.

Sometimes subtle behavioural changes, such as being quieter than usual or aggressive when handled, are also an indication of discomfort or pain. Less commonly, reduced appetite may also be seen. If you notice any of these signs, you should consider taking your rabbit to the vet as they may all indicate the onset of arthritis.

our vet will give your rabbit a full clinical examination. Radiographs will then confirm or rule out the presence of arthritis. On x-ray, arthritis joints will show a haze or fuzziness around the joint, which is diagnostic of the condition. Other more sophisticated diagnostic imaging techniques, including ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) and arthroscopy, can also be used for a more accurate diagnosis. All these techniques can prove very useful to visualize the degree of bone and joint destruction.

Your rabbit will probably require sedation or general anaesthesia in order to achieve good enough images to be diagnostic.

Your vet may also do a blood test, urine test, or take a sample of joint fluid (joint aspirate) to test in the lab to rule out any underlying problems.

It is possible to treat arthritis in rabbits in order to try and ease some of the discomfort and difficulties that the rabbit may be experiencing, but it is not currently possible to cure the problem completely.

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in rabbits to reduce inflammation around the joints and to ease the discomfort that is usually present with the condition. Your vet may want to check your rabbit’s liver and kidney function to safely prescribe these medications, especially if long-term treatment is required.

Septic arthritis can be resolved if it caught and treated early enough.

There has been controversy regarding supplementation of joint problems in both humans and animals; however there are some rabbit foods that now contain added glucosamine, which is thought to benefit animals with arthritis and help with joint mobility.

Gentle massage over the muscle of the affected area can help decrease the degree of muscle tightness. Gently flexing and extending the affected joint for a few minutes several times daily may help as well, but always remember that physical therapy may be detrimental in cases of trauma. Always follow your vet’s recommendation in these cases and be careful and gentle when handling your rabbit.

Acupuncture has also been reported to help in some cases by reducing the amount of pain medication used, and providing relief for many patients.

Ensure that you do not allow your rabbit to become overweight, and encourage them to exercise regularly to build up muscle mass.

If you think your rabbit may be developing arthritis (symptoms can be attributed to other conditions), then take your rabbit to see your vet as soon as possible.

If your rabbit is diagnosed with arthritis then keeping the hair clipped around the perineum and applying a barrier cream will help with any urine scalding, deep and soft bedding to prevent pressure sores is also recommended.

Keep your rabbit on a soft absorbent bedding to prevent soiling and further complications.

Your rabbits litter tray will need to have a low entrance if it is having difficulty hopping in and out, and if your rabbit has a ramp in their hutch/run or stairs, then you may need to make other arrangements as they may struggle to use these.

Some rabbits may not be able to reach their caecothrophes, so it is a good idea to collect them and place them in, or near to, their food area as most rabbits will eat them on their own.