Bumblefoot (ulcerative pododermatitis) is a bacterial infection and inflammatory reaction on the feet of birds and rodents. This infection is much more likely to occur in captive animals than in those in the wild.
Bumblefoot on birds of prey 
Bumblefoot is, perhaps, the largest cause of referral of birds of prey to a veterinary surgeon. Bumblefoot on birds of prey can be put into three broad types of the infection;
In the first type, a small reddened area, or sometimes a small shiny patch, can be seen on the foot. This is mostly caused by inappropriate perching (or perching for too long), or, less likely, by badly fitted furniture, such as jesses that are too small. To treat this type, one must change the fault in the husbandry, fly the bird regularly, and apply hemorrhoid cream to the affected foot.
The second type is more serious, where some penetration has occurred. While treatment for the first type will help, it is likely that the bird will require antibiotics as well.
The third type involves the bird having severe distortion of the contours of the foot and/or the toes, resulting from the Bumblefoot causing considerable damage in the foot.
Bumblefoot in poultry and waterfowl 
Bumblefoot is a common infection for domesticated poultry and waterfowl such as chickens and ducks. Due to constant walking on hard, rough, or sharp surfaces, birds can develop small wounds on the bottom of their feet. These wounds are very susceptible to infection by Staphylococcus aureus, bacteria which can cause bumblefoot in poultry and waterfowl. Treatment often requires opening the wound to drain the pus and antibiotic treatment and local application of pyodine as local dressing.
Bumblefoot in rodents 
Bumblefoot in rodents is caused by wire and mesh flooring and/or wheels that have not been cleaned for a while. This is due to a collection of urine and fecal matter collecting on the surface in trace amounts. To prevent Bumblefoot, a layer of cardboard and/or old clothing can be put over the wire mesh on the floor. This must be changed often, at least a few times a week.  The only rodent not affected is the gerbil, which has tougher feet and can safely walk on mesh and wire.
Bumblefoot is so named because of the characteristic "bumbles" or lesions as well as swelling of the foot pad symptomatic of an infection. Topical antiseptics such as Blue-Kote in addition to oral or injected antibiotics may be used to combat the infection, which if left untreated may be fatal.
- Ford, Emma. Falconry; Art and Practice. Cassell & Co 1992. Page 39/40.