Abomasal parasite counts (APC) were determined on 467 whitetailed deer (Odocoileus virginianus) collected in summer and 436 deer collected in fall from 50 localities in the Southeast. APC values declined from summer to fall region-wide. Declines in APC values began on most areas in Mountain and Piedmont provinces by October and November, respectively; and in the Coastal Plain province declines in APC values began in November. These differences in the timing of declines in APC values precluded establishment of region-wide guidelines for interpretation of fall APC values. Since APC values did not decline until November in Coastal Plain and Piedmont provinces, the sampling period for APC studies can be extended into October in these provinces. Abomasal parasite counts performed in October or later in the Mountain province and in November or later in Piedmont and Coastal Plain provinces are lower than summer APC values and shoUld be interpreted with caution.
