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by LBEMC Admin


ARTICLE: Deworming Protocols and Schedules

New parasitology research suggests that most of us are over-deworming our horses! The rotational deworming schedules that veterinarians have been recommending are actually based on science that is over 40 years old. These practices have caused a huge rise in parasite resistance because we have been unnecessarily deworming our horses every 8 weeks. If we continue to use these same practices, our current dewormers will no longer be effective. Researchers have found that only 20% of the equine population actually carries 80% of all parasites. By performing twice yearly Fecal Egg Counts (FEC), we will be able to identify each adult horse as a low, medium, or high parasite egg shedder and will then be able to tailor our deworming practices more specifically for each horse. This means fewer, more effective dewormings per year for each horse, less parasite resistance, and more effective dewormers for our future.


All adult horses should have a FEC performed twice yearly (Spring & Fall). Follow the recommendations below according the horse’s FEC result (*see note below for pregnant mares):

Low Shedders (<200EPG): Deworm twice yearly

  • Spring: Pyrantel Pamoate or Fenbendazole
    (It is recommended that low shedders get dewormed with Quest® or Panacur
    Power Pak® as the Spring treatment every other year to target encysted larvae)

  • Fall: Ivermectin/Praziquantel.

Medium Shedders (200-500EPG): Deworm three times yearly. NOTE: Veterinarian may consider doing FEC Reduction1 on this group

  • Spring: Pyrantel Pamoate or Fenbendazole

  • Early Summer: Quest® or Panacur Power Pak®

  • Fall: Ivermectin/Praziquantel

High Shedders (>500EPG): Deworm four times per year and do FEC Reduction1 yearly

  • Spring: Pyrantel Pamoate or Fenbendazole

  • Early Summer: Quest® or Panacur Power Pak®

  • Early Fall: Ivermectin/Praziquantel

  • Fall: Pyrantel Pamoate or Fenbendazole

*NOTE: We recommend not using Panacur Power Pak® or Quest® during pregnancy. Pregnant mares should not receive either of these products until after foaling.


Foal Schedule*

  • 2 months of age: Pyrantel pamoate (Strongid)- double dose

  • 4 months: Ivermectin

  • 6 months: Pyrantel pamoate-double dose

  • 8 months: Ivermectin/praziquantel (Equimax Plus or Zimectrin Gold)

  • 10 months: Fenbendazole (Panacur Power Pak)

  • 12 months: Ivermectin

*Where conditions warrant (e.g. large number of foals and/or premise contamination because foals are turned out on same ground each year) foals can be dewormed monthly up to 6 months of age. This can be accomplished by using single dose Fenbendazole in the regime at 1, 3, and 5 months of age.


Alternate Adult Schedule (every 2 months)

  • January: Ivermectin

  • March: Fenbendazole (Panacur Power Pak)

  • May: Ivermectin

  • July: Pyrantel pamoate

  • September: Ivermectin/praziquantel

  • November: Pyrantel pamoate

Alternate Adult Schedule (every 3 months)

  • January: Pyrantel pamoate

  • April: Fenbendazole (Pancur Power Pak)

  • July: Ivermectin

  • July: Pyrantel pamoate

  • October: Ivermectin/praziquantel

Daily Deworming

This program involves the daily administration of Strongid C (pyrantel) plus ivermectin and/or invermectin/praziquantel administered every 6 months. Daily deworming provides excellent deworming results if horses can be segregated for their daily feeding. The program should be started after a foal reaches a full year of age. If this protocol is included within Pfizer’s Preventicare program, the horse will be covered by a $5000 colic surgery insurance policy. LBEMC can provide the details.

1FEC Reduction involves performing a FEC before and 14 days after (21 days after if used Quest®) deworming with the recommended dewormer to check for parasite resistance. FEC should decrease by 90%.