Bumblefoot (infection)

Bumblefoot (ulcerative pododermatitis) is a common bacterial infection and inflammatory reaction that occurs on the feet of birds, rodents, and rabbits. It is caused by bacteria, namely species of Staphylococcus, Pseudomonas, and Escherichia, with S. aureus being the most common cause of the infection. The aforementioned opportunistic bacteria occur naturally in the animal's environment, and infection occurs when one or a combination of these enters the body through a scrape or cut in the skin.

Bumblefoot can take various forms, but it usually looks like an abscess-like swelling with a central, dark-colored scab that may or may not ooze. Sometimes, this swollen bump contains pus or cottage cheese-like material. Alternately, the swelling could contain a hard lump when these materials harden, or if the abscess becomes impacted with substrate (e.g. soil, straw, etc.) Bumblefoot may also present as redness, swelling, small red sores, and depending upon severity and length of time with the condition, lesions, cracks, or discoloration.

Lameness puts more weight-bearing duty on an animal's strong leg(s); this leads to excessive pressure being placed on the good foot (or feet), which increases the chance of an abrasion occurring that could develop a bumblefoot infection. Consequently, in cases of lameness, the good leg(s) should be examined for potential cuts and infections. Overweight animals are more at risk of developing bumblefoot for the same reason; their extra weight causes excessive pressure on their feet. However, the infection can usually be attributed to poor husbandry practices, so is much more likely to occur in captive animals than in those in the wild. Ulcerative pododermatitis is referred to as "sore hocks" when it affects a rabbit and "bumblefoot" when it affects a bird. The terms "sore hocks" and "bumblefoot" are used interchangeably when describing ulcerative pododermatitis in rodents.