How often should I deworm my horse??

Discussion in 'Horse Health' started by amandamarie, Aug 14, 2011.

  1. amandamarie

    amandamarie Full Member

    Jun 25, 2011
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    I moved my grandparents horses to my house so now i have the responsibility of caring for them. How often should I deworm them and should i switch dewormed each time? ive heard of them growing immune to it..
  2. coloredcowhorse

    coloredcowhorse Senior Member

    Aug 2, 2011
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    The horses don't become "immune" to the medication but the various worm species are developing resistance (sort of immunity) to some medications. The problem is that there are different species in different areas and climates and times of year....and some horses have a natural ability to not become badly infested while others have every species of worm there is. The best thing to do is contact your vet, collect manure samples following his instructions and have him do what is called Fecal Egg Counts (FEC's is what you will see abbreviated) will tell what kind and how many of most species and he can then suggest what to use and when. If you go to "" and sign in (free) you can search through their many archived articles on is a newer way of looking at treating horses for worms and is much more effective and in the long run less expensive and less likely to create resistant species of parasitic worms.
  3. creekridgefarm

    creekridgefarm Full Member

    Jun 21, 2011
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    This has a list of suggested dewormers. I deworm mine every two months and rotate the schedule as much as possible. There has been a lot of talk of horses becoming "immune" to dewormers lately, and some vets suggest doing a fecal check every couple months before deworming. I'd talk to your vet to see what they recommend... I think a lot of it is personal feelings regarding it and also your vet's input.
    1 person likes this.
  4. Ryle

    Ryle Senior Member

    Mar 4, 2006
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    Rotational deworming is an idea that has been out of date for many years. It was designed when we used different dewormers and had a different parasite problem. With the new dewormers, there is no reason to be deworming that often. In fact, many horses don't need deworming more than twice a year.

    Please take the time to read the deworming sticky thread at the top of this forum. I posted a really long-winded, in-depth message on why and how you plan a strategic deworming program. You can also go to and watch their hour long webinar on Strategic Deworming.
  5. PyroTekNik333

    PyroTekNik333 Senior Member

    Jul 22, 2008
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    A often as needed but as little as possible.

    Depending on where you live deworm for Tapes once to twice a year (with an Ivermectin/Prazquental paste) and talk with your vet about appropriate times to run fecal egg counts.
    When they run a FEC they can tell you what the horse is infested with (if anything) and what to deworm with (if anything) and if you run another fecal after treatment they can tell you whether it was effective or if you have a resistance problem.
  6. Guccijumper

    Guccijumper Senior Member

    Oct 9, 2010
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    Our barn does it every other month.
  7. slc

    slc Senior Member

    Feb 19, 2004
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    This is not the right way to decide how often to worm your horse.

    How often should be based on fecal counts that YOUR vet takes on YOUR horses.

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