Q. What species of parasites are identified in a fecal egg count test?

—Cecelia, West Virginia

A. It depends on who is doing the count and the type of procedure used. If we’re just doing a typical fecal egg count using a technique like the McMaster’s, which is a common method, we’re mostly looking at (small and large strongyle) eggs.

We can’t differentiate between the large and small strongyle eggs—all of the eggs look the same, although we know from research studies from over a number of years that well over 99% of the eggs we see in a fecal sample are from small strongyles