Horse Deworming in Orange County

Many old assumptions about worming are being challenged at this time. There is debate about how frequently horses should be wormed and whether rotation schedules should be “fast” rotation schedules, where a different product is used each worming, or “slow” where the same product is used several times in a row before switching to the next product in the rotation.

Also, concerns about parasite resistance are surfacing as more horses are being wormed with ever increasing frequency. Some large farms are beginning to be plagued with parasites which are highly resistant to worming medications which have been highly efficient in the past. These recent developments underscore the importance of a fecal exam on an annual or semi-annual basis to determine whether there are resistant parasites present. This fecal exam is done by suspending the fecal sample in a special solution, and then examining the sample under a microscope for microscopic eggs.

There are three main groups of wormers frequently used in a typical worming schedule today. Try to avoid focusing on the “name” of the product and focus instead on the active ingredient. This will allow you to frequently save money by purchasing a generic substitute if one is available. The three main active compounds used most frequently today are monoxidectin, ivermectins, and pyrantel pamoate. Each product has a different mechanism of action in the way that it kills the parasites in the horse. Each product has good efficacy against many of the common parasites, but with new resistances emerging, this is no longer a guarantee. Your EVA veterinarian can make specific suggestions which product or products are best indicated for use in your horse after getting the results of the fecal flotation exam from the lab.

Monoxidectin is very toxic to dogs! It also tastes good to dogs! If any medication drops out of your horse’s mouth onto the ground when you are administering the medication, pick it up. Do not leave it where your dog can lick it up. It is also a very good idea to dispose of the empty syringe very carefully in a trash can that the dogs cannot get into and chew up the empty syringe. A small amount can make a dog very sick, even on a small accidental exposure.