What Is It?
Ulcerative pododermatitis, or ‘sore hocks’, is a condition in rabbits characterized by ulcerated, infected areas of skin on the caudal aspect of the tarsus and metatarsus (rear limbs). It can also occur on the weight bearing surface of the metacarpus (front limb), though this is not as common. It is a serious, painful condition that can be progressive and difficult to cure once deep infection has set in.
Understanding the predisposing causes and progression of pododermatitis is essential in preventing and treating this disease. Rabbits do not have foot pads like dogs and cats. Instead, the skin and underlying structures form a tarso-metatarsal skin pad, with overlying thick fur. In a normal rabbit, the weight is distributed evenly between the claws and the metatarsus, further protecting this area from pressure necrosis. Anything that alters this normal anatomy or allows excessive pressure can lead to the development of pododermatitis.
Husbandry is very important in the prevention of this disease. Rabbits should be housed on soft, compliant surfaces. Towels with overlying newspaper or thick beds of hay are ideal. Grass exercise areas are also essential. Small cages which restrict exercise, or cages with hard surfaces (cement, tile), carpet, or wire will lead to excessive pressure on the metatarsal area. If the rabbit suffers from obesity, conformational deformities, or arthritis, abnormal stresses can be placed on the weight-bearing surfaces. Finally, damp dirty bedding or conditions leading to urinary or fecal incontinence can result in infection.
Ulcerative pododermatitis begins with a lack of blood flow and necrosis of the skin and soft tissue in the metatarsal or tarsal area, causing a pressure sore. The first sign is a hairless area of reddened skin. Once the area has lost its protective fur, it is more susceptible to trauma, friction, and pressure. Without treatment, this progresses to ulceration of the skin and subcutaneous structures and bacterial infection. Without aggressive therapy, erosion and infection of the bone, ligaments, and tendons can develop. At this stage, prognosis for recovery is grave.
Diagnosis
The diagnosis of ulcerative pododermatitis begins with a complete medical history and a thorough physical examination. Depending on the situation, your veterinarian may recommend a minimum data base consisting of a complete blood count, a serum chemistry profile, and a urinalysis, especially if urine scalding is exacerbating the problem. If the lesions are deep, radiographs of the rear limbs are essential to determine if osteomyelitis (bone infection) is present. If arthritis is suspected, radiographs of the spine and pelvis are warranted. Cytology and a culture of the lesion may be needed if it appears infected.
Treatment
Treatment of ulcerative pododermatitis is aimed at relieving pressure on the affected area, treating any secondary infection, and increasing mobility. Necessary changes in nutrition, housing, and exercise must be addressed. Your veterinarian will extensively discuss these husbandry issues with you if needed for your rabbit.
Ulcerated areas should be kept clean and dry. Liquid bandages (Nu Skin or Bandaid Liquid Bandages) are very useful in protecting the lesion. Traditional bandages may be attempted, but are difficult to keep on. Thick, dry, protective bedding is essential. Hair surrounding the lesion may be trimmed if long, but do not shave, as this is likely to worsen the situation. Appropriate antibiotics are indicated for any infected wound. Depending on the extent of the infection, surgical drainage or curettage may be needed. Analgesics, joint protectants, and/or acupuncture are also indicated in many cases, especially if arthritis is a predisposing factor. Treatment regimens are tailored to your individual rabbit’s situation.
This is a very serious disease which requires early diagnosis and aggressive treatment. Please consult your veterinarian immediately if your rabbit’s condition does not seem to be improving or is deteriorating.
Content prepared by St. Francis Animal Hospital, 1227 Larpenteur Ave. West, Roseville MN. 55113