What is the difference between Strategic, Evidenced-Based and Selective Deworming?


All three terms refer to the same method for controlling your horse’s internal parasites. 

Whether you call it Strategic, Evidenced-Based or Selective deworming, the method uses DATA to determine when to deworm your horse, which treatment product to use and provides feedback on the growing problem of parasite resistance.

The data comes from recently conducted fecal egg count tests.

Fecal egg count test results reveal the type and number of parasites present in your horse’s feces, which are an indication of what’s inside your horse.  This information allows you to determine IF your horse requires deworming.  If a deworming treatment is needed, a post-treatment fecal egg count test reveals the effectiveness of your horse’s dewormer and indicates potential parasite resistance patterns at your farm or barn.

Things to consider:

To Treat or Not to Treat – If your fecal egg count test indicates your horse has low parasite burden, you may choose not to treat him.  

A recent National Animal Health Monitoring Systems for equines has shown that 80% of the parasites on a property come from 30% of the horses.  So why treat 100% of your horses?  Besides wasting your time and money, you are needlessly pumping powerful chemicals into your horse.  That’s like you taking antibiotics when you are not sick. It doesn't help you get better, but it does help build resistance to the drug.

Life Cycle of the Parasite – Your horse consumes parasite larva while grazing.  The larva matures in your horse by “traveling” through your horse’s vital organs like a mole burrowing through a pasture.  Eventually, the larva takes up residence in your horse’s digestive system.  This is when parasites are most vulnerable to treatment.  However, during this stage, some parasites decide to extend their stay by encysting, meaning they burrow into your horse’s intestinal walls shielding themselves from dewormers.  Also, during this stage of development, parasites deposit their off-spring which are expelled back into the environment in your horse’s feces.

So Many Parasites, So Little Time - There are over 150 species of internal parasites or worms that can infect your horse. Probably the most important, regarding health risk, are small strongyles, roundworms, and tapeworms.  The chemicals contained in dewormers, kill parasites by either starving them to death or paralyzing them.  Because parasites or worms have no way of storing energy, they must eat almost continuously to stay alive.  Any disruption in this process results in energy depletion, therefore interfering with feeding for 24 hours or less is sufficient to kill most adult parasites.  Additionally, parasites will also die if they become paralyzed and temporarily lose their ability to maintain their position in the gut.  When choosing a dewormer carefully read the label and product literature for the type of parasites, it is meant to control.

Environmental factors – Seasons affect parasite population levels.  Parasites prefer warmer temperatures.  So, summer and fall are the favorite time of year for these unwelcome tourists. Plan on testing and treating your horse once in the Spring and again in the late Fall.  

What goes in your horse will eventually come out of your horse.  Keeping your horse’s stall, pasture and dry lot, manure free and clean year round is critical for preventing parasitic reinfection.  If done correctly a pasture hygiene program can nearly eliminate the need for deworming treatments.



Leave a comment

Please note, comments must be approved before they are published