Equine Parasite Management

October 16, 2011 by · 1 Comment 

If you have been paying attention the last year or so you have been hearing and reading that here in the US we have developed some resistant parasites in our horse population. How did we develop these resistant parasites? Well to be honest our deworming protocols. In our zeal to have a clean worm free horse population we have instead developed worms that are resistant to treatment. :-(

SO what to do? There are reports everywhere saying we should deworm regularly only with ivermectin, and others saying we should only deworm after testing to be sure our horse has parasites, and others still saying use a rotational deworming program but base it on the time of year rather than just every 30 or 60 days. However very little information is out there on how to actually prevent your horse from being infected in the first place. Well it is a matter of equine parasite management.

In equine parasite management one needs to first consider the actual risk of your horse being infected by parasites. The risk for a horse stabled and fed inside a barn and turned out by itself in its own personal dry lot is going to be much less than another horse that is kept in a small pasture with 5 other horses. With a horse in the environment as the latter, it is going to be near impossible to prevent infection from parasites, so one has to be dedicated to management of the pasture to prevent an overabundance.

The rules of equine parasite management –

  1. Clean up the manure in the pasture/turnout – a minimum of once a week this reduces the amount of eggs being delivered to the pasture and also the larva.
  2. If you feed hay and/or grain, feed inside the barn or at a minimum in a bunk off the ground and in an area separate from the pasture. If you do feed in a bunk outside place the bunk on a concrete pad or limestone. Clean feed buckets and bunks regularly.
  3. If possible divide your pastures and rotate the usage allowing a rest period to help kill off parasites.
  4. Test each horse’s manure regularly (once every 2-3 months) for parasites. One horse can be a high shedder and be the main infector and another have a very low parasite count. Knowing the high shedders will help you manage those individual horses and keep them separate from the rest of the herd if possible. Also you can treat the horses that shed and treat each horse as an individual which actually helps the entire herd.
  5. Deworm any new horse prior to introducing them to your herd.
If you use these five steps you can lower the risk of your horse being infected with parasites, then you do not have to worry about what you have to do with the deworming schedule or if you have to rotate or what product you have to use, because you will have a lower risk of parasite infection.

Other Sources for deworming and horse parasite control

Two Horses, Adjoining Pastures–Two Wildly Different Deworming

The worm load for the mare? Very small–only 34 (which is the number of eggs per gram), which makes her a “low shedder” of worm eggs. According to thi.


A Chilling Thought About Horse Deworming Schedules | MyHorse

Like you, I’ve read many conflicting horse deworming schedule reports. And it seems that for every horse deworming program based on a rotational drug.


Every Horse Boarder’s Nightmare: A Young Horse’s Death from Severe Worm Damage and the Ten Commandments of Parasite Control

From the very day that newly-initiated horse owners pick up their crisp new how-to horsecare book or go to that first horse health lecture, the first commandment of horse health management echoes in their ears: Thou shalt worm thy horse religiously.


A cute video explaining the new concepts for deworming –


Eggzamin Superworm – Drug Resistant Parasite in Horses. Time to rethink our deworming strategies.

About Dr Daniel Beatty
An Infopreneur with a Veterinary Medicine degree.