The parasite population is shared between all the horses present on a farm, but that doesn’t mean all horses have identical deworming needs. | Photo: iStock

Q. What’s the best way to go about making the decision to deworm if my horse is boarded at a large facility? For instance, historically my horse has tested as a low to no shedder, and he only goes out with two other horses. Should we have the recommended three fecal test this year and then decide? Are there other considerations to keep in mind?

Let’s say all three horses test as low to no shedders, and the recommendation is not to deworm. Any suggestions for effecting change at a farm that follows tradition (i.e., generally they deworm all the horses without fecal egg counts)?

—Louise, via