Ulcerative pododermatitis, also known as bumblefoot, is an inflamation of the balls of the feet of birds, guinea pigs, rabbits, and rats. The inflamation is usually caused by infection with Staphylococcus aureaus, but may be caused by other bacteria. The infection occurs when the bacteria contacts broken skin, such as a wound or abrasion, on the foot. Rats can get abbrasions on their feet from walking on wire cage flooring or rough textured cage litter.

Bumblefoot usually appears first as a small, reddish bump or lump on the foot. It can look similar to a corn or callous you see on human feet. Inside the lump is a closed abcess. In progressed stages the lumps grow large and can break open and bleed.

The best treatment for bumblefoot in rats is a combination of a systemic antibiotic (Cefa Drops) and topical applications of an antiseptic/disinfectant, (Dr. Naylor BLU-KOTE). Some people have seen faster improvement by cleansing the feet with chlorhexidine, an antiseptic/disinfectant solution, between BLU-KOTE applications.

The best prevention against bumblefoot is a clean, disinfected cage with solid surface floors and soft cage litter.

References:

Saunders Comprehensive Veterinary Dictionary, Second Edition D. C. Blood and V. P. Studdert, 1999

The Biology and Medicine of Rabbits and Rodents by John E. Harkness and Joseph E. Wagner