Pododermatitis, also referred to as "bumblefoot" and "sore hocks," most commonly occurs in guinea pigs and rabbits. It usually affects the bottom of the hind feet and hocks (the lower part of the back leg that touches the ground when the animal is sitting). In rabbits, the hind feet are more frequently affected, whereas guinea pigs more commonly have problems on the front feet. "Podo" refers to the foot, and "dermatitis" refers to inflammation of the skin.
What causes pododermatitis?
Excessive pressure on the foot may cause loss of hair and calluses. It may also damage the skin causing open wounds and infection of the tissues of the feet. The infection may even spread to the bones. The pressure most often occurs if a large rabbit is housed on a hard floor or if a guinea pig is housed on a wire floor with no access to a solid floor. It is more common in hot, humid weather.
Factors that may predispose an animal to developing sore hocks and feet include:
Loss of hair on the foot, which may be the result of heredity (Rex breeds of rabbits)
Housing on a wet surface (e.g., damp resting board, or wet bedding), which can soften the feet and predispose to infections
Large size or obesity, which puts more weight on the feet
Lack of movement in a small cage
Abrasions from rough, irregular, or wire floors
Poor sanitation, which results in a large number of bacteria in the environment
Inadequate vitamin C in the diet of guinea pigs
In rabbits, repeated thumping of the hind feet
What are the signs of pododermatitis?
Animals with pododermatitis may start favoring one of their feet or appear lame and reluctant to walk. There may be loss of hair on the affected foot, thickening of the skin, swelling, redness, and sometimes open, draining areas or scabs. It is a painful condition and guinea pigs may vocalize if it is severe. Some animals may become depressed and not eat.
Radiographs (x-rays) may be taken to see if the infection has entered the bone (a condition called 'osteomyelitis.') A bacterial culture and sensitivity are often performed so the correct antibiotic can be chosen. Certain antibiotics can cause serious, and sometimes fatal digestive problems in rabbits and guinea pigs, so only use the antibiotics prescribed by your veterinarian.
How is pododermatitis treated?
For mild cases (slight swelling and redness), simply changing the environment and diet of the animal may be all that is needed. This may include providing:
A smoother floor
Softer and thicker bedding
Dry surfaces
Increased cleanliness
Increased vitamin C for guinea pigs
Fewer calories to overweight animals
For any foot problem that is more severe, veterinary attention is needed. Radiographs (x-rays) may be taken to determine if there is any bone infection. The animal will be placed on antibiotics and pain relievers, if indicated. Surgery may be necessary to remove any dead or dying tissue. The feet may need to be repeatedly soaked and bandaged with topical dressings.
What is the prognosis for animals with pododermatitis?
Mild cases generally respond well to management changes. With more severe cases, however, the prognosis is guarded. It is often difficult to control the infection and keep the foot kept clean since bandages are often not tolerated well. In unresponsive cases, amputation may be necessary.
How can pododermatitis be prevented?
Sore hocks and feet can easily be prevented by providing the right environment and diet for the animal. Measures include:
Good sanitation: regular cleaning of the cage and litter box
Good flooring: smooth and dry
Soft, thick, dry, clean bedding
Daily checking of the feet
Good diet and preventing animals from becoming overweight
Clipping toenails
Providing a large enough cage or area for exercise