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.
What is pododermatitis?
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.
What are the common causes of pododermatitis in rabbits?
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.
What tests will my vet use to investigate pododermatitis?
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.
What treatment options are there?
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.
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.
What is the prognosis?
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.
How do I reduce the risks to my rabbit?
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.