Pododermatitis in Guinea Pigs

Pododermatitis (a foot infection), also called "bumblefoot," is a common and sometimes difficult condition to treat in guinea pigs. It normally occurs in obese animals housed in wire-bottomed cages or abrasive bedding. Areas of hyperkeratosis develop on the palmar and plantar surfaces of the feet, which then ulcerate and become infected with Staphylococcus aureus.

In general, pododermatitis is caused by poor husbandry conditions like improper housing, obesity from overfeeding and poor sanitation. Many cages sold for guinea pigs have wire bottoms with improper dimensions. Guinea pigs, unlike rabbits, do not have fur on the bottom of their feet so there is not much padding or protection from injury. The wire is a very rough surface and will predispose them to superficial wounds, which then become a source of infection.

Obesity is common in guinea pigs because they love to eat and will continue to eat if given the opportunity. It is also hard to say "no" to a guinea pig who is chirping or whistling for a treat. On top of that, their pellets are compressed and processed and make it easy for them to consume a lot of calories quickly. Obesity puts an increased amount of weight on their feet and predisposes them to pressure sores.

Poor sanitation provides an environment for bacteria to flourish and increases the exposure of your guinea pig to infections. If your guinea pig stands on soiled and wet bedding, his feet will become softened by the moisture which will allow bacteria to invade into the footpads.

Guinea pigs with pododermatitis have one or more extremely swollen feet. The bottom of the affected foot is often times ulcerated and scabbed over with blood and bedding material. They can be painful and cause your guinea pig to limp or hold up his foot.

Diagnosis

• Radiographs (X-rays) are an important initial diagnostic test to help determine the extent of the infection. If the infection has spread into the bone (osteomyelitis) the prognosis is poor.
• Bacterial culture is also very helpful. It allows your veterinarian to identify the specific bacterial pathogen and determine which antibiotic would be most effective at fighting the infection. Staphylococcus aureus is the most common bacteria isolated. Treatment with an inappropriate antibiotic will delay healing and gives time for the infection to invade further.

Treatment

• Surgical debridement (removal of excess unhealthy tissue) may be necessary in severe cases. Guinea pigs produce a large amount of granulation tissue which can interfere with proper healing.
• Systemic antibiotics (whether injectable or oral) will fight off the infection. The antibiotic used may be changed depending on the culture results.
• Correcting any husbandry problems and instituting a gradually weight loss program will prevent recurrence or worsening of the infection.

Home Care and Prevention

Optimal treatment requires a combination of home and professional veterinary care. Antiseptic foot soaks will help treat the infection topically. Once or twice a day, the affected feet can be soak in a betadine or chlorhexidine solution.

Soft bandaging will prevent further infection from contaminants in the environment and may make your guinea pig more comfortable. Providing soft, clean bedding will also help speed up recovery.

Remember that giving oral antibiotics may disrupt their normal gastrointestinal bacterial flora. Probiotics such as Lactobacillus can be given concurrently to help prevent that.

Follow-up appointments and routine rechecks are important to make sure that the affected feet are doing well and healing. This is a very long process and your veterinarian will be able to help evaluate how the feet are progressing.

House your guinea pig on clean, soft bedding material and off of wire. If you have a wire bottom cage, remove the wire or place enough bedding to cover it. Feed your guinea pig an appropriate amount to prevent obesity. Restrict the amount of pellets and treats if there is a weight problem.

Maintain proper sanitation. Your guinea pig should not be housed on soiled or wet bedding. Routinely examine your guinea pig, including the feet. If you do see any injuries or wounds to the feet, have them examined and treated as soon as possible.