From November of 1994 to June of 1996 an epizootic of mange, probably caused by the mite Notoedres cati, occurred in white-nosed coatis (Nasua narica) in the tropical dry forests of the Chamela-Cuixmala Biosphere Reserve in western Mexico. A monitoring scheme to determine the extent and severity of the epizootic within coatis was implemented. Trapping periods and transects were conducted for 2 yr. To control the spread of the disease, all captured infected coatis were either euthanized or treated with acaricides such as Butox® and Ivomec-F®, depending on the severity of their infection. Four other species of wild mammals and feral cats had skin conditions resembling mange. A more severe problem with the disease was predicted and later confirmed in the less isolated areas of the reserve, with a higher density of coatis. Our results indicate that epizootics may be more prone to occur in areas with greater fragmentation and less isolation from anthropogenic influence. Interestingly, although there was an apparently severe impact of the mange epizootic in the coati population, the long-term impact of the disease is unknown but appears to be negligible. So in order to understand the role of diseases in wildlife populations, long-term experimental studies are required.