Davidson Chinchillas - Specialising in Charcoal Chinchillas

 "Bumblefoot" (or ulcerative pododermatitis) is a condition which is characterised by ulceration of the feet. It is a chronic condition which occurs when the skin on the feet cracks and ulceration develops. Both the skin and the surrounding walking areas are covered in bacteria which does no harm as long as the skin remains intact (unbroken). When the skin is broken bacteria gets into the wound and can cause problems. If the ulcers are not treated quickly bumblefoot can develop (see Kiera  & Bummble's stories for examples - also see Azure Chinchillas page  here.).

It may be that bumblefoot develops in a similar manner to that of diabetic foot ulceration in humans. In diabetic foot ulceration there is intense unrelieved pressure which continues to necrotise (kill) the tissue. The ulcer continues to deteriorate and cannot heal because every step the patient takes puts more pressure on the foot (twice the body weight at least) which destroys any granulating (healing) tissue.
That combined with increased susceptability to infection (due to the diabetes) leads to further complications and possible infection in the bone (osteomyelitis).

Foot ulcers require intensive wound management (in both humans and chinchillas), underlying condition management, nutrition, and pressure relief with specialist footwear of various types (not possible with chinchillas!). In humans it can take months or years to heal these types of ulcer and bony infection is sadly common - amputation, debridement (removal of dead or unwanted tissue, usually by surgery), and systemic infection can follow - massive doses of strong antibiotics may be required and some patients require extensive hospitalisation.

The pathology of bumblefoot may happen as follows:

callus formation (hard skin on the chin's back feet) and constant unrelieved pressure ( from mesh cages) causes an inflammatory response - serous fluid builds up under the callus because of the inflammation and constant friction from the pressure of walking, which in turn leads to further pressure because the fluid fills the space between the callus and the underlying tissue (similar to blistering). The fluid has to go somewhere and usually the callus cracks/splits and the fluid leaks out - the crack in the callus then allows bacteria in and infection occurs.
The infection can develop un-noticed under the callus and can quickly lead to osteomyelitis (infection in the bone) which then causes further problems and exacerbates the ulceration.

Large chins seem particularly prone to bumblefoot/ulceration because the pressures will be similar to that in patients with diabetic foot wounds and sadly there is not much we can do in the way of pressure relieving footwear for chinchillas. It is possible to treat chinchillas with bumblefoot with varying degrees of success, as the two case studies (Kiera and Bummble) illustrate.