Just What Is It?
Pododermatitis is commonly known as bumblefoot. It is an infectious disease process that affects the feet of birds who are overweight, inactive, have bad perches or are chronically ill. Damage to the bottom of the foot (the plantar surface) can also be an instigating factor of bumblefoot.
This is a well known disease of raptors – the earliest known English reference of the disease published in the “Boke of St. Albans” in 1486. Presumably since falconry has been around since possibly 2000 BC (based on earliest accounts) and the earliest known image of falconry is dated at approximately 700 BC, there are earlier records of this disease.
Who Gets Bumblefoot?
Raptors, Anseriformes (ducks and geese), Psittaciformes (parrots) and Sphenisciformes (Penguins) are the most common groups to develop this condition.
Why Does It Occur?
There are 2 basic ways infection can set it: first via a puncture in the skin of the base of the foot (a talon, a thorn, foreign object…) and second by pressure sores on the bottom of the foot. Pressure sores occur because of uneven weight bearing that leads to damage and devitalization of the skin. Lack of exercise, poor diet, inappropriate perches (too wide, too narrow, too rough), weight gain/obesity, damage to the other foot causing increased weight bearing on the “good foot” and overgrown nails or talons causing the bird to stand inappropriately.
Both of these events lead to infection of the skin with bacteria and occasionally fungi. Once the process begins it leads to a series of changes which eventually may damage the tendons of the foot or spread to other joints and even the heart.
Stages of Bumblefoot
There are several classification schemes for bumblefoot. This disease is dynamic so divisions between the stages may seem somewhat arbitrary. The fact remains that the earlier this issue is caught, the simpler the treatment.
Early stages show loss of the scale pattern on the foot, redness and mild swelling. This can often be easily treated with topical softeners such as bag balm, improvement of the diet and modification of the environment – get rid of those bad perches!
Moderate stages usually require surgical intervention. The changes that lead to infection also reduce the ability of antibiotics to get to the problem. Debridement of the wound, surgical removal of damaged tissues and bandaging are all reasonable treatments.
Later stages are very serious and life threatening. Since the development of antibiotic impregnated beads we can treat later stages than we used to. Prosthetics may even be a solution for birds such as ducks that cannot survive with only one good foot.
A Pigeon’s Tale
This King Pigeon was found in the city- they don’t survive long in the wild so she was lucky to be picked up and brought in. We don’t know her history so we don’t know how her feet got to look like this…
You can see the large swelling of the foot with a big scab in the middle. In Wendel’s case, the scab was easily removed, revealing thick scar tissue that didn’t bleed.
Scar tissue like this just won’t go away without surgery. So we removed it!
Wendel’s doing great now and both her feet continue to look normal.
Bumblefoot, It’s Not Just For Birds
Sadly, pododermatitis can occur in our rats and guinea pigs as well. Similar to birds, an infection gets into the foot pad via trauma that may be induced by inappropriate substrate (wire grates or abrasive substrate) but poor diet and obesity are also factors.
Here is a mild instance of bumblefoot in a guinea pig followed by a foot with severe changes:
Here is an image of moderate changes in a rat:
Unfortunately it is more difficult to treat this disease in Guinea Pigs and Rats. Soaking, disinfecting and bandaging are the keys. But it may be impossible to keep bandages on their feet or the infection may have spread into the bones.
Some Guinea Pigs, like Oscar here, don’t seem to mind the bandages!