Seasonal influence on testicular function of male raccoons, Procyon lotor.

In order to clarify the breeding capability of male raccoons in Japan, the testes of raccoons, a nuisance animal, collected in Kanagawa Prefecture and Hokkaido were histologically inspected. Furthermore, testosterone concentrations in their blood were measured. The testosterone concentrations increased in winter and the diameter of seminiferous tubules and the spermatogenetic score decreased in summer for the animals captured in Kanagawa Prefecture.