Chinchillas have long been admired for their characteristically beautiful fur. When roaming free, they instinctively free their fur of dirt and oil by rolling around in the dust formed from finely ground volcanic rocks. The need to clean their dense fur is no different when they are in captivity. Accordingly, a chinchilla dust bath should occur several times a week to keep the fur as clean and as healthy as possible.
Inherently, wild chinchillas do not clean themselves by going into water, as this may prevent their dense fur from drying properly. Moreover, if moisture is retained closely to their skin, this may actually cause a fungus growth or the fur to rot. A water bath would also wash away the natural, protective oils that help chinchillas control their internal body temperature. It stands to reason then that a water bath should be avoided and open water bowls should never be placed in chinchilla cages.
To properly care for chinchillas, providing them with an opportunity to take dust baths is the best way to ensure healthy fur and skin. Placing about one inch of volcanic ash in a small glass bowl should be adequate. Be sure to allow your chinchilla to roll around as needed, and remember that the frequency of bathing is dependent upon your particular climate. A chinchilla kept in captivity in a more humid climate, for example, may require more frequent dust baths than one kept in a drier environment.
Ideally, each bath should be allowed to last for about twenty to thirty minutes. In reality, a chinchilla will most likely stop rolling around and cleaning its fur before this much time has elapsed. As a precaution against being exposed to too much dust, be sure to use a separate bowl. Cages for chinchillas should not have a permanent bath house without a lid to limit the amount of exposure to chinchilla dust because even though wet fur is a health hazard, so too is skin that is flaky and dry.