One topic horse owners have heard a lot about in the past few years is anthelmintic resistance. And while many veterinarians encourage their clients to change to fecal egg count (FEC) directed deworming from rotational deworming—something many have practiced for years or decades—some are slow to adapt. But new study results from Scotland suggest that FEC-based deworming could have added benefits to horse owners: Researchers believe FEC-directed programs will not only help preserve current dewormers’ efficacy, but could also save horse owners money in the long run.

“Not all horses need deworming,” relayed Hannah Lester, BSc, MSc, MVPH, a student at the Moredun Research Institute, in Edinburgh, Scotland, and lead researcher in the study. “The majority of horses will have a low or negative FEC, and we typically see that 80% of the high FECs are in 20% of horses." This means only about 20% need aggressive deworming treatments, she said.

To find out which method is most cost-effective, the team compared the annual costs of an FEC-directed deworming program used on 368 horses at 16 equine facilities with the projected costs of an interval deworming program (reportedly used by the majority of questionnaire respondents in a previous study) for the same number of horses