Horse De-worming

Basics on horse de-worming.
Learn how to properly de-worm your horse.

The traditional method for horse de-worming is every 6-8 weeks, but that may be slowly changing.

There are fairly new discussions and research on the de-worming topic ohow often to de-worm your horse. There is not a lot of information yet supporting the new debate. De-worming every 6-8 weeks may be too often and could be doing more harm than good? It is possible that de-worming your horse too often can cause your horse to get immune (resistance) to the de-worming medication, therefore causing the medication to not work.


The first and most important thing to do is contact your veterinarian to put together the best de-worming program for your horse.


There are many things that can affect your horse and how to properly manage parasites (worms)….

  • Location
  • Number of horses pastured together
  • Age
  • Pasture management
  • How you rotate your de-wormers

The best way to get an idea of what parasites your horse may have is to get a fecal worm count done. This can be done by your veterinarian or you can purchase a fecal test kit. This will inform you specifically which parasites to target.


Different climates and temperatures can have different affects on parasites. Depending on where you live will help you determine the best de-worming program for your horse. Talk to your vet to discuss your region’s climates for parasite control.

Number of Horses Pastured Together

The bigger number of horses pastured together, the bigger the risk for parasite infestation. Rotating grazing pastures can also help reduce the risk. (Find out the best rotation time period for your state and location for the different seasons.)

Pasture Management

horse de-wormingKeeping your pasture, paddocks and barns cleaned and mucked out plays a huge role in parasite control. Horses pass parasites through their manure and when they graze and nibble around that same area, the parasites are re-ingested to start the cycle over again.

Spreading manure on your pastures can be a great option if you have the means and area to do so because it has nutrients for plant growth. Be sure to compost all manure before spreading because this kills parasites and larvae.

Spreading fresh manure can cause a risk for parasite re-infestation. Don’t spread when the ground is frozen or wet because this will prevent the nutrients from getting into the ground.


The age of a horse is relevant when determining the best solution for your de-worming program for your horse. Talk with your veterinarian for the best options for your horse.

How You Rotate your De-wormers

Rotating your horse’s de-wormer greatly affects parasite control. This doesn’t mean to just buy a different brand name of the same kind of de-wormer that you used last. You have to use another type of de-wormer that has a different chemical base in it.  (I will explain below).

When you rotate to a different de-wormer, you have to change up the chemical class in them. there are many de-wormers on the market that have different brand names but have the same chemicals or ingredients in them, More and more parasites are becoming resistant to certain de-womers because they are being overused and not properly rotated.

There are 3 different chemical based (class) de-wormers

  1. Macrocyclic Lactones
  2. Benzimidazole
  3. Pyrimidine
  • There is another chemical base de-wormer that “technically” don’t fall into the sa
    me categories (has its own class) and is combined with macrocyclic lactones…
  1. Praziquantel – targets tapeworms.

Macrocyclic Lactones

→ Active ingredients: Ivermectin & Moxidectin

– Products (brand names)

  • Ivermectin Paste (ivermectin)
  • Horse Health (ivermectin)
  • Ivercare (ivermectin)
  • Quest (moxidectin)


→ Active Ingredients: Fenbendazole & Oxibendazole

– Products (brand names)

  • Anthelcide (oxibendazole)
  • Safe-guard (fenbendazole)
  • panacur (fenbendazole)


→ Active ingredient: Pyrantel Pamoate

– Products (brand name)

  • Pyrantel paste (pyrantel pamoate)
  • Strongid (pyrantel pamoate)


→ Active ingredient: Praziquantel

– Products (brand name)

  • Equimax (praziquantel/ivermectin)
  • Zimectrin gold (praziquantel/ivermectin)
  • Quest plus (praziquantel/moxidectin) is a great place to look for de-wormers

120x60 general
If there is something you would like to ask or a comment you would like to leave, please do so. Thank you for stopping in and reading my page. Have a wonderful day!  Michelle



4 thoughts on “Horse De-worming”

  1. Interesting article. I had no idea how complicated it is to keep your horse healthy. It more than mucking out the stalls regularly and high quality feed. I had a horse for a while but found the upkeep overwhelming in regards to how much time I had to spend with her. I will keep your site on reference for when I can get back to horse ownership, they are such amazing animals!

  2. Hi Patricia thank you, i really appreciate you keeping my site handy. I hope you are able to get another horse. Mine are my go to when I need some quiet time to myself. All the best to you.


  3. This was a really insightful article. I will admit that I know absolutely nothing about horses, but this really gave me a good perspective as to what horse owners go through with their horses.

Leave a Comment