The epizootiology and pathology of sarcoptic mange in coyotes, Canis latrans, from south Texas.

An epizootic of sarcoptic mange in coyotes from south Texas, Canis latrans , was studied over a 7-yr period, 1975 through 1981. From a four-county area centered in Webb County, Texas the epizootic radiated centrifugally to include a 27-county area. The disease progressed from initial, scabby encrustations on the ischium and fore and hind legs to severe, thickened, slate-gray hyperkeratotic lesions with almost complete alopecia. There were significant decreases in alpha-globulin and albumin, significant increases in gamma-globulin, and significant decreases in fat deposits and total body weight indicative of a chronic infection with establishment of a humoral antibody response as the infection progressed in severity. Significant differences in prevalence of mange across habitat variables of host age and sex, and across seasons were related to the juvenile/adult ratio in the coyote population at any particular time because the infection progressed more rapidly in juveniles. Population dynamics and abundance of coyotes were generally unaffected by the mange epizootic. Although higher mortality was associated with mange-infected animals, this had no effect on overall mortality in the coyote population.