Sore hocks (pododermatitis) in rabbits

 

 

Esther van Praag Ph.D.

 

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Warning: this file contains pictures that may be distressing for people

 

Pododermatitis is a skin disease and a musculoskeletal problem, whose origin is multifactorial. Adult rabbits are more often affected than young rabbits, larger breeds more than smaller. The major cause is trauma, due to the pressure on the sole caused by running on rough and/or abrading floors (e.g. rough carpets, tiles, vinyl or wire flooring of cages), more rarely by regular thumping of anxious or nervous rabbits. Poor hygiene in the cage can be a further cause for pododermatitis.

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Flemish giant rabbit putting weight on his hocks, instead of toes.

Genetics play a role too. Rabbits belonging to the Rex breed have feet padded with short soft fur that brings little protection. In Angora rabbits, shaved for their hairy coat, hair must never be shaved away from the bottom of their feet. Some rabbits also have a wrong physical body position. Instead of putting weight on the toes (rabbits are digitigrades); they place weight on the metatarsus and hock. Others position their hind feet wrongly, by stretching them too much to the front. In both cases, an enormous pressure is exercised on the hock, leading to pressure sores, ulcers and abscesses.

The various causes all lead to a decreased blood circulation in the hind limb, more rarely in the forelegs. Lack of oxygen supply (ischemia) causes tissue necrosis. A pressure sore is formed, which can develop into an ulcer or an abscess. The infection spreads to deeper located tissues, which can lead to the infection of the lymphatic nodes, the bone (osteomyelitis), or general sepsis. At this stage, the condition is very painful, and the rabbit will avoid walking, becomes incontinent for both urine and feces. Reduced movement reduces proper blood circulation in the limbs. A vicious circle is thus created, and the general condition of the rabbit decreases rapidly.

In cases where the bone is affected, the ligaments and the tendons can be displaced, which leads to permanent invalidity. This condition is easily recognized by the special gait of the rabbit, with a refusal to put pressure on its toes, and use of hocks instead.

Diagnosis

It usually starts with a hairless spot on the sole. The skin is thickened, inflamed and red, with necrotic tissue in the middle of the wound. Ulcers and abscesses can be present. The bacterial infection can be accompanied by the presence of purulent white paste-like pus. If the wounds remain untreated, the infection will spread to the inner tissues and can lead to the infection of the lymphatic system, the bone (osteomyelitis) or general sepsis. The rabbit is usually restless, with a decreases appetite and weight loss.

Paula Carter

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Naked skin of the sole of hind feet in rabbits. Left: a healthy foot with a line of naked pinkish skin is found when combing to the side. Right: rabbit suffering from pododermatitis.

Clinical signs

The clinical signs and the behavior of the rabbit are usually enough for a proper diagnosis. In the case of bacterial infection is present, cultures of samples taken from the infected area can help confirm the presence of either Pasteurella sp. or Staphylococcus aureus, but other bacteria have also been found. It is thus highly recommended to do a bacterial cultured, accompanied by a antibiotics sensitivity test.

When pododermatitis is left untreated, the condition will progress.

·           Stage 1:    alopecia on the sole, due to compression of the hair follicles in the dermis, accompanied by a thickening of the skin (epidermic hyperplasia and parakeratosis, or abnormal keratinization of the skin). No bleeding is observed.

·           Stage 2:    the skin is thick and shows epidermic hyperplasia and parakeratosis. Small bleeding is observed. Appearance of a callosity. The rabbit suffers pain at this stage.

·           Stage 3:    naked, thick and hard skin, with crusty hyper and parakeratosis. Pressure sores may develop. Necrotic tissue is observed in the dermis. Healing is extremely difficult at this stage.

 

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Flora, a young female Rex rabbit suffering from pododermatitis on the front feet (left) and hind limbs (right).

 Treatment

The treatment of pododermatitis needs to be on two levels:

Find the cause of pododermatitis, which includes a thorough examination of the environment where the rabbit is living and improve it, a reduction of weight in case of obesity, accompanied by increased exercise possibilities.

It is recommended to clip the hair around the wound, so that it cannot reach the wound anymore but remains long enough to protect the rest of the foot sole. The wound needs to be disinfected, e.g. with povidone-iodine, after which a antiseptic cream can be used. Good results were obtained with the following antiseptic products:

-  Salicylic acid 0.006%;

-  Mupirocin 2%;

-  Neomycin 2%;

-  Manuka honey;

-  HEALx cream;

-  Calendula/Echinacea 5% gel (Powervet®, Switzerland).

The use of systemic cephalosporin or azythromycin have proven efficient in the treatment of abscesses that developed secondary to pododermatitis. The antibiotic treatment should be done over a longer period of time, eventually for lifetime.

If pododermatitis is accompanied by pain, analgesic should be administered to the rabbit, e.g., meloxicam, which can be used over a longer period without appearance of side effects in rabbits. The reduction of pain usually encourages the rabbit to move more, which is on its turn beneficial for the blood circulation of the wounded leg. If this is not the case, soft massages of the limbs can help activate blood circulation in the affected limbs.

Bandaging the feet may be helpful. This can be by mean of a liquid plaster that produces an impermeable layer while allowing breathing of the skin. Regular bandaging material can also be used, but must be changed regularly to avoid infection.

Rabbits are skillful bandage removers. It is therefore sometimes useful to make a wire according to the size of the foot. This metal tube can be filled with padding material, e.g. cork, in such a way that the wounded area is left unperturbed and without pressure.

Ulcerative pododermatitis is often difficult to treat and recurrence is common.

Linda Baley and Claudia Misceo

Bambi, a 5 year old female Rex rabbit suffering from pododermatitis on the hind limbs, demonstrating bandaging of her hurt feet with soft padding and elastic adhesive bandage.

 

For detailed information on pododematitis in rabbits,

Skin Diseases of Rabbits

by E. van Praag, A. Maurer and T. Saarony,

408 pages, 2010.

 

Acknowledgement

A special thanks to Arie van Praag, Paula Carter, Sandy Minshull, and Linda Baley, and Claudia Misceo for the pictures of rabbits with pododermatitis.

Thank you also to Flora and Bambi for their patience.

Further Reading

Jong IC, Reimert H, Rommers JM. Effect of floor type on footpad injuries in does: a pilot study. 9th World Rabbit Congress, Verona, Italy. 2008, 1171-76.

Drescher B, Schlender-Boebbis I.  Pododermatitis (" Sore hocks") in the rabbit. Kleintierpraxis 1996:41: 99-103.

Graham JE. Rabbit wound management. Veterinary Clinics of North America: Exotic Animal Practice 2004:7:37-55.

Harcourt-Brown F. Skin diseases. In: Textbook of Rabbit Medicine. Oxford, UK:Butterworth-Heinemann; 2002 p 233-240.

Henfrey J. Common dermatoses of small mammals. In Practice 1993;15:67-71.

Hermans K, Devriese LA, Haesebrouck F. Rabbit staphylococcosis: difficult solutions for serious problems. Vet Microbiol 2003;91:57-64.

Hoppmann E, Barron HW. Ferret and Rabbit Dermatology. Journal of Exotic Pet Medicine, 2007:16;225-237.

Rommers JM, Meijerhof R. 1996. The effect of different floor types on footpad injuries of rabbit does. In: Proc 6th World Rabbit Congress, Toulouse, France 1996;2:431-436.

Rosenthal KL. How to manage the geriatric rabbit. www.floridarabbit.org Accessed: November 2008.

 

 

 

 

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