Fipronil-Treated Deer Feed Exposure

At the initiation of the deer feed exposure period, deer were presented exclusively with FDF in an elevated livestock feeder (Additional file 2: Figure S1). A maximum of 1 kg was presented to deer every 24 h, and deer were provided commercial deer diet immediately upon consuming all FDF. Each morning of exposure (08:00 a.m.) the FDF was removed temporarily and weighed to the nearest 0.1 g, after which fresh FDF was immediately presented to the deer. At the conclusion of the exposure period, all FDF was weighed and permanently removed. The above procedures were also followed for the deer in the control group, but they were presented with an untreated placebo (containing all ingredients of FDF minus fipronil) rather than FDF.