Horse Wormer: What Horse Worming Schedule Should I Use?
Choosing a horse worming schedule for your herd can be an overwhelming experience for sure. In the past the theory of worming horses was that there was no harm in treating a horse even if he didn't need it. Better safe than sorry. Today, researchers are seeing an increase in the parasite's resistance to the drugs we are using so it is imperative to treat each horse with a worming schedule made exclusively for them. With these simple steps you will be well on your way to having a precise worming schedule for each of your horses.
Fecal Egg Count: Make arrangements with your veterinarian to have a manure sample from your horse evaluated. The lab will dilute a portion of the feces in liquid and then take a look at it under a microscope. They will count the number of parasite eggs in the sample and determine at what rate your horse is shedding eggs. Some horses harbor high parasite numbers while others carry a low burden. From this test your vet can help determine the best course of action for your horse. Have your horse tested in the spring and/or fall before deworming them.
Egg Shedding Rate: The parasites that infest horses lay eggs that are shed through a horse's feces. Those eggs then get ingested while your horse is grazing. The eggs incubate in the horse's gut, hatch into larvae, mature into worms and lay eggs which get expelled with the horse's manure and the cycle continues. Horses that have higher numbers of parasites shed more eggs and should be treated accordingly. Researchers have determined that only 20% of the horse population is responsible for 80% of the parasite population. That means that only a handful of horses are high-egg shedders and should be treated aggressively. The other 80% of the horse population only requires moderate parasite control.
Life Cycle of Most Equine Parasites:
Rotating Horse Wormers: It is still common practice to rotate the type of horse wormer you are using. Be sure to rotate between drug classes, not just the brand name of wormer you're using. Rotating your horse's wormer will help decrease the risk of developing resistance.
CLICK HERE for a printable version of this chart.
A Few Good Strategies:
Treat for Bots after the frost or in early winter.
Treat for Tapeworms at least once a year in the spring or fall.
Treat for encysted small strongyles once a year in the spring or fall.
Deworm your entire herd of horses at the same time.
Scrape off any bot eggs that may be on your horse's jaw, flanks, legs or anywhere else on the rest of their body.
If you choose to start a daily horse wormer regimen, be sure to purge your horse of parasites before you begin.
Giving your horse proper food and water will also help control worms.
Deworming strategies tend to be very location specific; this is why we recommend you consult your veterinarian before starting any new deworming regimen.
Horse Worming Schedule: West Michigan Veterinary Service has an excellent parasite control flow chart that includes suggested deworming schedules for high, medium and low shedding horses.
With growing resistance of parasites to drugs and our ever evolving knowledge of equine parasites we now know how important it is to have a customized worming schedule for each horse on the farm. Be sure to give your veterinarian a call to set up a fecal egg count test before you deworm this spring. Your vet will then help you devise a region-specific deworming schedule for each horse. Then shop online at www.MillbrookTack.com for all of your horse wormer needs.
**ALWAYS CONSULT A VETERNARIAN BEFORE STARTING A NEW HORSE WORMING SCHEDULE**
**Foals, Pregnant Mares and Ponies have different deworming needs and requirements than most other horses**