Sawdust is notorious for causing eye and nose problems, and this will be evident more in some individuals than others. It would seem likely that your gerbil is in fact allergic to his bedding, so you have done well in recognizing this and taking responsibility for your gerbil’s well-being.

One reason sawdust can cause such problems is because it is so fine, and easily penetrates the eye and nose. Pine sawdust smells nice because it releases volatile compounds such as phenol. Unfortunately these same compounds have been implicated as a potential health risk – possibly causing respiratory problems and changes to the liver. Because of this, Aspen is often used as an alternative.

Alternatives include paper-based cat litter, peat, sand and straw. As with all substrates for use in the home, make sure they are sterile or at least thoroughly cleaned.