Bumblefoot (infection)

Bumblefoot (ulcerative pododermatitis) is a common bacterial infection and inflammatory reaction that occurs on the feet of birds, rodents, and rabbits.^[1] It is caused by bacteria, namely species of Staphylococcus, Pseudomonas, and Escherichia, with S. aureus being the most common cause of the infection.^[1] 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.^[2]

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.^[3] Sometimes, this swollen bump contains pus or cottage cheese-like material.^[3] Alternately, the swelling could contain a hard lump^[3] when these materials harden, or if the abscess becomes impacted with substrate (e.g. soil, straw, etc.)^[3] 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.^[2]

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.^[2] Consequently, in cases of lameness, the good leg(s) should be examined for potential cuts and infections.^[2] Overweight animals are more at risk of developing bumblefoot for the same reason; their extra weight causes excessive pressure on their feet.^[2] However, the infection can usually be attributed to poor husbandry practices,^[1][4] 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.^[1] The terms "sore hocks" and "bumblefoot" are used interchangeably when describing ulcerative pododermatitis in rodents.^[1]