Pododermatitis is a spongy, moist, inflamed callous on one or both heels, often infected. It occurs almost exclusively in heavy, elderly bucks.

The condition is extremely hard to treat. It is possible to keep the callous clean and dry up any infections, but the callous itself always seems to recur, even if surgically removed. However, encouraging the rat to paddle in a dilute solution of Tea-Tree oil is said to bring some relief from both swelling and infection.

In extreme cases the condition can lead to infection in the capsules of the hocks, which is painful and very difficult to treat. I have know it take six weeks on Genticin (super-powerful antibiotic which can - and did - damage a rat's hearing if used long-term like this) to shift such an infection.

Wire-floored cages and/or shelves are not a good idea as these increase the risk of pododermatitis, which seems to be essentially a kind of pressure-sore. Very soft bedding would probably reduce it.