Category: skin-disease-rabbits

Pododermatitis in rabbits – sore hocks

Disruption of the normal stance or locomotion in rabbits may lead to pressure sores on the base of the feet, known as pododermatitis. Starting as a skin problem, this condition progresses over time to affect deeper tissues and can be extremely debilitating.

Pododermatitis is basically a pressure sore, with inflammation occurring where the feet are in contact with the ground. Damage to the blood supply leads to deeper inflammation and infection. Once the skin is damaged, bacterial infection can easily occur. Left untreated, the skin problem progresses to affect other tissues, including tendons and bones in the foot.

The back feet are usually affected, since they support the majority of the rabbit’s weight, though the front feet may also be affected; the rabbit’s stance may be abnormal. This condition is painful and other clinical signs you may also see include reluctance to move, anorexia/reduced appetite, depression and/or aggression and bruxism. Obesity may be present as a predisposing factor, although weight loss may occur due to anorexia. This condition may be fatal if pain leads to anorexia or if infection spreads to the rest of the body.

An increase in pressure on tissues in the base of the feet may occur for several reasons:

  • Giant breeds are more at risk as the incidence increases with weight.
  • Overweight or pregnant inactive rabbits put excessive pressure on the base of their feet.
  • Poor conformation or a leg/spinal injury may lead to increased weight-bearing on a specific foot.
  • Pain may cause the rabbit to move around less.
  • Arthritis may lead to the rabbit adopting a different gait and weightbearing abnormally.
  • Elderly rabbits that become inactive may bear weight abnormally.
  • Rabbits whose claws are allowed to become overgrown regularly will lead to the rabbit placing more weight on the back of the feet.

The skin will become damaged more easily in certain instances:

  • Removal of the thick fur, by shaving or clipping, from the base of the feet removes this protection. Rex rabbits have less skin protection than other breeds due to their lack of guard hairs and thinner coat.
  • In rabbits housed on surfaces which are hard, such as grid flooring, or abrasive, such as carpeting, the feet can be damaged and become infected.
  • The skin is also easily damaged in rabbit kept on wet or soiled bedding/litter.

The most common infection involved is Staphylococcus aureus, but other bacteria can also infect the inflamed tissues.

Pain due to tissue damage and infection in turn leads to less mobility and a vicious cycle in which the condition worsens.

After examining your rabbit, the vet may suggest some other tests to assess the extent of the condition before advising on the best treatment:

  • Blood tests can show the overall health of your rabbit, in particular identifying signs of infection.
  • Xrays and ultrasound are primarily used to assess whether deep involvement of tissues is present in the foot. They can also be useful to check for other conditions that may predispose pododermatitis, e.g. arthritis.
  • Sampling from lesions for testing of bacteria helps your vet choose the best antibiotic to use, while other laboratory tests like histopathology can rule out tumours.

Your vet will probably use the results from these tests to grade the pododermatitis:

  • Grade I: early disease with no symptoms.
  • Grade II: mild disease with intact skin.
  • Grade III: moderate with ulcers/scabs present.
  • Grade IV: severe with abscess formation and deeper tissues affected.
  • Grace V: severe and often irreversible, as bone infection occurs and tendon damage results in a permanently altered stance.

Addressing any underlying causes is paramount, including providing an appropriate substrate for the rabbit. Often medical therapy will merely alleviate the condition.

General treatments include:

  • Provide soft, dry bedding for your rabbit (vetbed is very useful).
  • Provide an appropriate diet, supportive feeding if anorexia is present; correct obesity by increasing fibre/decreasing carbohydrate intake. Weight loss must be done slowly to avoid hepatic lipidosis.
  • Trim overgrown toenails.
  • Clean the feet.
  • Topical ointments may be used to help protect the feet from further trauma or infection.
  • Some cases benefit from dressings (though some rabbits won’t tolerate them). Most importantly, ensure the dressing is kept clean and dry.
  • Anti-inflammatories/pain relief.
  • Restrict activity if tissues are severely damaged, but encourage activity in the long-term.

More specific treatments may be appropriate for certain diseases, e.g. antibiotics for infections or surgery to address deeper disease. General anaesthesia is required if surgery is performed.

The prognosis depends on the grade of pododermatitis at the time of diagnosis. Early detection and treatment greatly improves the prognosis.

Grade I-III lesions can be treated, though your rabbit may have recurrence of disease.

If deeper tissues are affected, tendons can become permanently and irreversibly damaged; for Grade IV-V lesions, the prognosis is guarded to poor.

Good care of your rabbit will reduce the risk of many diseases. Clean any soiled/wet litter daily and encourage exercise.

Provide your rabbit with a balanced diet and an appropriate environment in which to live.

Avoid the following to reduce the risks of pododermatitis:

  • Hard or abrasive surfaces in your rabbit’s environment.
  • Wet, urine- or faeces-soaked surfaces.
  • Clipping the fur from the hocks, especially in Angora rabbits.
  • Stressing your rabbit, nervous rabbits traumatise their back feet when they stamp!
  • Excessively warm/humid environments.
  • Obesity.

Lice infestation

Rabbits can host a variety of parasites on their fur and skin. These are termed as ectoparasites, since they live on the outside of the rabbit. Lice fall into this classification and can be a problem for pet rabbits.

Clinical signs of a lice infestation may include pruritus (intense scratching), bald patches within the fur or thinning of the fur.

With advanced infestations, the rabbit may appear very agitated, restless and may also lose weight and eat less because they spend so much time scratching. Anaemia may also be present, especially in very young rabbits, as lice feed by sucking the rabbit’s blood. This is especially noticeable in albino rabbits which will appear very pale. Severe anaemia can cause weakness and even death.

The rabbit louse is Haemodipsus ventricosus, and is a sucking louse, but is thought to be rare in pet rabbits. They are normally found along the back and on the sides of the rabbit as well as around the rump area. Adult lice are visible with the naked eye and can be seen moving. The eggs (nits) are oval in shape and are laid and firmly attach to the shafts of the hair, these can also be seen with the naked eye. The entire lifecycle from egg to louse takes 2-5 weeks where environmental conditions are at an optimum.

Ivermectin injections at 7-10 days apart for 3-4 treatments are normally effective. Treatment needs to last long enough to eradicate the eggs as they hatch.

Imidacloprid (Advantage®) is effective in dogs and could also be used in rabbits.

Do not use fipronil (Frontline®) in rabbits as it has been associated with toxicity.

There has been some discussion as to whether or not the rabbit louse can act as a vector for myxomatosis. In theory, if a louse from a myxomatosis infected rabbit found its way onto a domestic rabbit this is potentially possible, although in reality an extremely unlikely possibility.

However, it is recommended that all rabbits are vaccinated against myxomatosis, which now, with the new combined myxomatosis and viral haemorrhagic disease vaccine (Nobivac Myxo-RHD), only requires an annual booster.

This has not been documented, since the lice are species specific, but it is wise to get your rabbit treated as soon as you notice any symptoms, and to clean the environment after every treatment.

Flystrike in rabbits

Vets know that with the arrival of the warmer months, comes the common problem of rabbits affected by flystrike being presented to them. This is a deeply distressing condition for owners, the veterinary team and especially the rabbit, which is literally being eaten alive. However, with some simple preventative measures, hopefully your bunny will never have to endure this condition, or if they are unlucky enough to be affected, you will be able to act quickly enough so they are one of the lucky ones who can be saved.

Certain species of flies (e.g. bluebottles), use other animals as a host to lay their eggs on, which hatch into maggots, and then proceed to eat into the flesh of the animal, causing immense suffering to the animal, which in essence is eaten alive.

Flies are attracted by soiled or wet fur, usually around the tail area of the rabbit, but any area can be affected, or any open wound, cut or scratch. Once laid, the eggs will hatch into maggots within 12-36 hours, burrowing into the rabbit’s flesh, causing vast tissue damage and pain, which can prove to be fatal even with prompt veterinary treatment.

The months of April to October are quoted as being the months when animals are more susceptible to flystrike, but it has been reported to have occurred in rabbits as early as January or as late as November, so owners need to be vigilant throughout the whole year, but extra vigilant during the flystrike season of April to October.

Any rabbit, even those kept as house rabbits who keep themselves beautifully clean, can be affected by flystrike; it only takes one area of soiled fur/skin or scratch, and one fly. However, not surprisingly those most at risk are rabbits who have frequent dirty bottoms, so ensuring that your rabbit is clean and dry is the best prevention against this awful condition. If your rabbit is often affected by a dirty bottom then, along with your vet, you need to ascertain the cause of the problem in order to treat the underlying condition, whilst also being extra vigilant in spotting the first signs of flystrike.

Possible causes of dirty bottoms include:

  • Dental disease making cleaning too painful.
  • Spinal problems making cleaning difficult or painful or causing difficulty in adopting the correct position to eat the caecotrophs (normal soft droppings produced by rabbits which are eaten direct from the anus as they are produced).
  • Balance problems unable to adopt the correct position to clean themselves.
  • Obesity too fat to reach their bottoms to keep clean or retrieve the caecotrophs.
  • Incorrect diet leading to too many caecotrophs being produced.
  • Too much dried food filling up on this and so not hungry enough to eat the caecotrophs, which then get left and stuck to the tail area.
  • Old age not able to keep themselves clean.
  • Urinary tract diseases, causing incontinence or abnormally smelly urine.
  • Disease of the uterus of female rabbits, because of the abnormal odour associated with discharges, and also because disease of the uterus is painful and can stop the rabbit grooming itself.

Longhaired rabbits are also more susceptible to flystrike, because of the amount of fur they have and faeces are more likely to get caught up in the fur, and, as aforementioned, any bloodied area (cuts or wounds etc) will also attract flies.

As far as flystrike goes, prevention really is better than cure and cannot be stressed enough, and even if your rabbit isn’t classed as being at high risk of developing flystrike, it is still imperative you still do as much as you can in preventing them from contracting it low risk, doesn’t mean no risk.

Ways on trying to prevent flystrike include:

If possible, treat any condition which places the rabbit in a high risk category.
Consider spaying does which are not used for breeding (there are many other benefits to this procedure too).
Ensure that your rabbit isn’t overweight and is fed a correct diet.
Check the whole rabbit, paying special attention to the back end and tail area, at least twice a day, going through the fur to check for soiled/wet fur or maggots.
If the rabbit has a dirty bottom, clean it for them immediately.
High risk rabbits may be safer inside the house, but must still have their bottom checked twice daily.
Clean litter trays daily and remove all soiled bedding from hutches daily.
Staple net curtains over the hutch/run to insect proof them.
Consider using Rearguard (Novartis Animal Health). Rearguard is a liquid which is applied to the tail area of the rabbit by sponge, and should any eggs be laid on the area it will prevent them from hatching into damage causing maggots. Rearguard is available from veterinary surgeons, but if using this you must still check your rabbits bottom area.

You may not be able to see any actual maggots as they may be concealed under matted or soiled fur (especially in long-haired rabbits), so if your rabbit is displaying symptoms such as restlessness, irritation, ‘wetness’ or abnormal odour around a certain area (usually the tail area), lack of appetite, sudden aggression etc, you should take it to your vet immediately. If you suspect flystrike and your veterinary surgery is closed, then you must phone an emergency on-call vet.

If you can see any obvious maggots remove them with tweezers as quickly as possible, but do not put the rabbit into water in an attempt to wash off some of the maggots. Clippers don’t work very well on wet fur and your vet may be delayed in treating your rabbit if they have to dry the fur first. The longer a rabbit is left the more damage the maggots will cause, which may be impossible to treat, with the only option of putting the rabbit to sleep, to stop it suffering any longer, so time really is of the essence.

Cases of flystrike can be successfully treated if caught early, but this is dependent upon the amount of damage caused by the maggots and if your vet feels that the rabbit has a reasonable chance of recovery. It is also necessary to take account of any underlying diseases such as dental disease which may also affect the likely outcome.

If your vet feels that the rabbit has a reasonable chance of recovery then treatment usually consists of:

Clipping the fur from the affected area to assess the damage.
Washing and removing all visible maggots.
Surgery to remove any concealed maggots, necrotic (dead/infected) tissue and repair tissue damage.
Antibiotics to prevent a secondary infection or treat infection if one is already present, fluid therapy and other treatments to counteract the effects of toxins that may have entered your rabbit’s bloodstream, and painkillers to make your rabbit more comfortable.
Identifying the cause as to why the rabbit was affected with flystrike and treatment to correct any underlying problem.
Rabbits will need to be anaesthetised for surgery and often rabbits affected with flystrike are suffering to some degree with shock, and so will carry a higher anaesthetic risk.

If the rabbit does survive, the wounds can take weeks to heal and during this time the rabbit will be at an increased risk of further bouts of flystrike and also infections, so careful nursing by the owner will be required and preventative treatment measures must be stepped-up.

Claire King, The Rabbit Welfare Association.

Ear canker in rabbits

Ear canker can be a painful and irritating condition for your rabbit. Signs of this condition tend to appear 2-3 weeks after the animal is first infested with mites, therefore early detection of the mites that cause ear canker is important when trying to prevent this condition from taking hold.

Ear canker is a condition of the rabbit’s ears caused by the ear mite Psoroptes cuniculi. Psoroptes cuniculi is a common parasite of rabbits and occurs worldwide. The mites irritate the lining of the ear which causes oozing serum and thick crusts to accumulate within the ear canal. Lesions can spread to the face and neck and perforate through the eardrum leading to middle ear disease (otitis media).

Ear mites cause the rabbit intense irritation, so you will notice your rabbit headshaking, ear flapping and scratching at the ears more often than usual. More severe signs may include twisting of the head (torticollis) and spasms of the eye muscles.

If you look down the rabbits ears you may notice crustings and scabs down the ear canal. The rabbit may resent you touching the ears as the condition is also very painful.

Long-term suffering can lead to further problems where the rabbit may lose skin from the ears and succumb to secondary infections which can damage the inner ear and may reach the central nervous system (CNS).

If you suspect your rabbit has ear canker, you should take it to see your vet as soon as possible, since the longer you leave it before treatment the more serious it will get and the longer the rabbit will suffer.

The recommended treatment is Ivermectin injections once every 10-14 days for three treatments or Moxidectin injection once every 10 days for two treatments. All in-contact animals should be treated even if they are showing no symptoms. Mild infections may be treated with eardrops.

The systemic treatment should be sufficient to resolve the crusty lesions down the ears, but if necessary they can be removed by being softened in mineral oil before being very carefully removed. Care must be taken not to damage the lining of the ear canal and your vet may need to sedate your rabbit to carry this procedure out safely.

Painkillers (analgesia) in the form of a non-steroidal anti-inflammatory drug (NSAID) may also be prescribed to help with the pain and irritation the condition causes.

All bedding within the cage/hutch should be disposed of (preferably burnt) after each of the rabbit injections. Hutches should be carefully cleaned and disinfected to ensure there are no mites present which may cause further infections.

Biting and nuisance flies

The most common flies that affect rabbits include green bottles, house flies, face flies, stable flies, horn flies, horse flies and blow fly species. Some species, like blow flies, are attracted to moist decaying environments in which to lay their eggs. Other fly species such as face flies, flesh flies, screw worm flies and bot flies target living animal flesh, including drinking the tears of live animals, biting the animal for a blood meal, or reproducing by laying eggs under the animal’s skin.

Flies are insects that are characterised by a pair of wings. Their ability to fly gives them the ability to travel large distances in search for food or a suitable environment to reproduce.

Their keen sense of smell draws them to foodstuffs, decay, excrement and moisture, and these are frequently found around animals, this makes animals a prime target.

The fly’s extraordinary mobility makes infestation and disease transmission between animals a real concern.

One of the most common conditions resulting from fly infestation in rabbits is flystrike (a type of myiasis).

This condition begins when female flies are attracted to moist soiled fur where they lay eggs that hatch into voracious larvae (maggots). The larvae crawl and eat their way through the decaying excrement and broken down skin causing a rapidly expanding open wound that can be life-threatening.

Signs of flystrike include:

  • moist matted fur
  • hair loss
  • reddened skin
  • foul odour
  • visible wounds
  • the presence of eggs and larvae/maggots in the fur

The rabbit may act weak, depressed, lay on its side or have an abnormally hunched posture. It may have a reduced appetite, or be reluctant to move. In severe cases, it may even lose consciousness or experience seizures.

Treatment for fly strike involves physical removal of the larvae and soiled fur followed by careful wound care and attention to secondary infection and pain control. Treatment is not always successful in advanced cases where the wounds are large or deep.

To prevent flystrike it is essential that the rabbit has clean dry fur, especially during the warm summer months when flies are most active. It is imperative that the housing environment is free from excess moisture and that the area is regularly cleaned of faecal matter and soiled bedding. Screened enclosures can help prevent flies from entering the habitat. In addition, all rabbits should be checked each evening to ensure that the body, and especially the undercarriage and hind end is free from excess moisture and debris and that no eggs have been laid. Failure to do this can result in significant damage in just a few short hours as eggs hatch and larvae migrate over the body.

Rabbits most at risk of flystrike are those that are obese and unable to reach their hind end. It is important that the rabbit is able to reach its hind end to groom itself and to consume soft faecal pellets (caecotrophs) which are essential for digestive health. Lack of grooming can lead to fur becoming matted with debris and faecal matter. Additionally, failure to ingest caecotrophs can lead to poor health and diarrhoea, another leading cause for flystrike.

Good bodyweight and intestinal health in rabbits requires a high fibre diet. Rabbits should eat at least 80% quality grass or meadow hay (not alfalfa hay) supplemented with fresh dark green leafy vegetables and herbs and only about 5% high quality fresh rabbit pellets. Sweet vegetables and fruits should only be fed occasionally as a special treat as the high carbohydrates can negatively affect digestion.

Another type of myiasis is caused by parasitic flies that have larvae that burrow into the skin or tissue of the rabbit. The majority of these species belong to the Cuterebra family which are primarily found in North America.

Bot flies lay eggs in a variety of places including near open wounds or orifices. They can even lay in moist soil in an animal enclosure or on other insects to transmit the larvae to the host.

Once a larva is on a host, it can burrow under the skin where it will sit and develop using host tissue as a source of energy. Some of these larvae can travel to the respiratory or gastrointestinal tract, or into the eyes and nose.

Clinical signs of infestation can include swelling, pain, ulceration and discharge around the larval cyst with secondary bacterial and fungal infections being common. The wound can cause distress to the rabbit and in severe cases can cause depression, weakness and serious infection.

Treatment includes careful physical removal, followed by cleaning and treatment of the wound.

Prevention is difficult as the flies are attracted to the host, even in clean conditions, but screens can deter some. Regular daily inspections of the rabbit’s skin and fur can help detect problems before they become severe.

Flies can also transmit dangerous diseases; both viral haemorrhagic disease and myxomatosis are viruses that are spread by biting flies, and both diseases can prove fatal.

Clinical signs include swelling of the eyes, face and genital as well as blindness, difficulty eating, drinking and breathing.

Treatment for these diseases in not guaranteed with the majority of cases proving fatal, although early detection and intensive care can improve outcomes.

Prevention of fly transmitted viruses is relatively easy via vaccination.

Biting flies can still be a real nuisance to rabbits causing painful bites and wounds on the ears and face; screened enclosures can do wonders to help provide a safe and comfortable habitat.

It is also essential to provide a clean, dry enclosure for your rabbit which can decrease the incidence of attracting flies in the first place.

Alopecia – hair loss

Alopecia is also known as hair loss, and it typically means partial or complete hair loss on areas of the body where hair is normally found. Alopecia can occur in virtually all animals with hair and is normal in some situations (such as baldness in human males). In most animals, however, it is usually an abnormal condition which can come on suddenly or progress over time, depending on the cause. Alopecia can be unsightly and reduce the insulating and protective capacity of a rabbit’s coat, potentially leading to increased stress and/or development of other conditions for the animal.

A rabbit with alopecia can have small areas of localised baldness, larger patch areas of hair loss, or even generalised hair loss over much of the body. Other signs of hair loss include clumps of hair seen in the rabbit’s environment or within the animal’s faeces. If the rabbit ingests too much of the hair, this can lead to intestinal blockage.

Alopecia is generally caused by disease which disrupts normal growth at the hair follicle, or from physical extraction of the hair. The pattern of hair loss on the body and the extent to which it has occurred will help determine the cause of the problem.

Physical extraction occurs when the rabbit pulls hair out as a result of hormonal or psychological influences, e.g.:

  • Pregnant does (female rabbits) may pull out their own hair from around their dewlap and stomach. This fine hair is used to line the burrow before giving birth. Does are more likely to pull large quantities of hair if they are stressed or if there is not enough quality nesting material present. Similar hormonal changes in a doe with false (or pseudo-) pregnancy can cause the same behaviour.
  • Compulsive hair chewing (barbering) and over-grooming are abnormal behaviours usually related to stress such as overcrowding (territorial bullying) or as a result of insufficient dietary fibre. For animals that self-traumatise, baldness will typically be isolated to those areas of the body that the animal can easily reach with its mouth, leaving the head, face and back of the neck unaffected. For animals that are chewed upon by others, the pattern of hair loss tends to be along the spine or on the head.

Internal disease causing alopecia has many different causes and appearances, eg:

  • In rare cases, rabbits are born with a hereditary condition causing alopecia.
  • Autoimmune disorders, nutritional deficiencies, tumours or side effects from medications commonly result in multiple areas of hair loss or larger areas of hair loss.
  • Trauma from scratching viral, bacterial, fungal or parasitic infections can cause localised patch alopecia with flaky or scabbed skin.
  • Small localised patches can result from trauma as a result of wounds, including bite wounds or other injuries such as burns.
  • Heavy moulting can result in larger areas being affected but does not usually result in complete baldness of these areas.

In many cases, the cause of alopecia can be determined by observing the pattern of hair loss and patient history. If a diagnosis isn’t readily apparent after a thorough physical examination, your vet may need to explore further causes to determine the source of the problem. Some of these diagnostic procedures include microscopic examination, lab tests and diagnostic imaging.

Microscopic examination

Samples of skin or hair are examined to look for fleas, lice, mites, fungus, bacteria or yeasts. Usually collecting these samples is painless or relatively painless for your rabbit. Results may be quick if the source is obvious but more complicated cases require sending the sample to an external laboratory. Testing for fungal infection by culture may take two weeks.

Laboratory tests, biopsies and radiography

Blood tests, urine tests, biopsies and radiography may be useful in determining if there is an autoimmune disorder, tumour, internal infection or other hidden cause. This can usually be done quickly with a day stay in hospital, and results are usually back within a few days if samples are sent to an external laboratory.

Fortunately, in most cases of alopecia, the hair will eventually grow back but specific treatment may be required.

Medications may be necessary to treat heavy parasitic, bacterial or fungal diseases. Wounds, hormonal and autoimmune conditions may require treatment of symptoms until the clinical signs resolve. Tumours may require removal and chemotherapy. Improvements in nutrition and husbandry can help resolve behavioural causes of alopecia. The time period and cost of treatments depend on the cause of the alopecia.

To help reduce the incidence of alopecia, ensure your rabbit is happy and healthy. The rabbit’s environment should be safe, secure and non-stressful. Ensure the housing offers shelter as well as space where the rabbit can exercise and exhibit normal behaviour. Provide environmental enrichment such as places to hide, nesting material, toys to play with, wood for chewing, herbs to browse, and soil to dig in. Prevent overcrowded housing which can be stressful and promote unnecessary spread of disease. Reduce the likelihood of territorial aggression by avoiding housing your rabbit in close quarters with others that are un-neutered or of the same sex.

It is also important to ensure a strong immunity and healthy gut function (that will help prevent faecal soiling of the fur) by offering good quality grass hay as the staple diet with high-fibre pellets and fresh green vegetables to supplement. Minimise environments where parasites can thrive by removing soiled bedding and faeces promptly, and by regularly cleaning and drying the housing environment.

You can reduce the likelihood of over-grooming by ensuring your rabbit is well-groomed, especially during periods of moulting or if it is a long-haired breed.

Finally, ensure prevention of disease by having your rabbit seen at least yearly by your vet for an all-over health check and dental examination. You should provide rapid treatment of disease by consulting with your vet at the first sign of any abnormal signs, such as lack of appetite, changes in drinking or urination, changes in activity level, hair loss, scratching, excessive grooming, drooling, teeth grinding, changes in hair coat, faecal soiling, fly strike, and limping.