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November 30th, 2018

Horsemen’s Laboratory,

John Byrd D.V.M.

Tel: 217-586-2004

Photos are available on request.

Media Contact:

Tel 607 434 4470

By Nikki Alvin-Smith

The stark reality about dewormers and their use in horses, is that worms of variant types are becoming resistant to the products currently available on the market. According to experts in equine parasitology there are no new dewormer products on the horizon. So as a horse owner you probably don’t want to ignore the fact that you are either contributing to the dewormer resistant problem, or are one of the growing number of enlightened horse owners that are taking responsibility by not following an ancient unsustainable protocol in equine worm management.

How do you know if you are doing the right thing? The answer is a hard NO if you answer YES to any of the following:

  • Are you a horse owner that uses a variety of anthelmintics on a random rotational basis?
  • Do you deworm your horses based on a fixed calendar schedule?
  • Do you treat your herd of horses before moving them to a new pasture?
  • Do you deworm your horses based on the weather, such as immediately after the first frost?

So are you guilty of following an antique protocol that may be contributing to a dewormer resistant equine worm population? Unfortunately the arbitrary nature of these aforementioned actions does nothing to target the worms with an efficient treatment. They waste your money, subject your horse to unnecessary chemicals and make little sense in the modern world of equine parasitology. But it’s not too late to fix things.

Think about why you deworm your horses in the first place? Presumably, you wish to optimize your horses’ health and performance. Excellent! That’s a great premise. How do you know if you are being successful in achieving that goal? Bear in mind that a horse can show no outward signs of the presence of worms, but as host his immune system or other mechanisms may be compromised by their presence.

Should you worry about dewormer resistance and do you know how to check your herd for the issue and know what you can do to try and mitigate its presence or perhaps even prevent it happening in the first place?

Many boarding barns insist that all horses are dewormed on a set schedule and many horse owners follow along blindly. The blind leading the blind! It is important to understand that no deworming program will entirely destroy all parasites in the horse or his environment. The goal is to minimize the presence of infective parasites in both the pasture and the herd, and to enact control measures that are customized for each particular farm.

The only method to do this is to utilize an evidence based targeted deworming program, and that means you need to test your horses scientifically using a fecal egg count test (F.E.C.T.). This testing will provide you with an indication of what worms are present and in what numbers and most importantly, in which members of the herd.

Once you have these results you can evaluate your present treatment protocol, administer any necessary adjustments with a dewormer targeted for the particular type of worm, follow the worm’s lifecycle and retest. The retest or fecal egg count reduction test (F.E.C.R.T) can be completed at the appropriate time interval after dewormer administration, to ascertain whether there has been a significant reduction that is expected of 90% – 95% worm egg count. If this has not occurred, you may have a dewormer resistant parasite population and other treatments should be enacted with the advice from your vet or equine parasitology expert. It is important that your entire horse herd population be tested and not just one horse in order to obtain an accurate picture of the possible contamination with infective parasites.

Knowledge is a powerful tool in horse health management. With the clear scientific evidence from leaders in equine parasitology such as Dr. Martin Nielsen and Dr. Craig Reinemeyer amongst many others, that dewormer resistance is a real issue, please think about becoming an active part of the solution in combating the overuse and misuse of anthelmintics.

Unlike some countries in Europe, where dewormers are only available by prescription, we are fortunate in the U.S.A. to be entrusted to buy our deworming products over the counter and administer them as we see fit. Always follow directions as to dosage and never over or underdose. Use a weight tape to measure your horse, ensure that each horse receives the entire required dosage and that it isn’t spit out or lands on your new barn coat! Follow an up to date protocol that is evidence based. Note that some dewormer product manufacturers have recently changed the packaging so check each product carefully for changes and go by the instructions on the label.

We all need to preserve dewormer efficacy for our horses’ benefit and if we all step up to help it will make a positive difference for us all. Testing is simple and convenient to do. Kits can be purchased online for the purpose. Follow the collection instructions and mail them in. Results will be emailed, and if you need help managing those results or advice on what products to administer and when, consult an equine parasitology expert.

PLEASE NOTE: This article is available for use in its entirety without edit or excerpt, in any media format on condition that credit is given to Horsemen’s Laboratory, and author Nikki Alvin-Smith as a byline at the beginning of the article publication. Horsemen’s Laboratory URL address and Nikki Alvin-Smith URL must be included. We would appreciate notification of any publication via email to media contact Thank-you for sharing!

This article is brought to you courtesy of Horsemen’s Laboratory Inc., Mahomet, IL. –

About Horsemen’s Laboratory: Established in 1993 by John Byrd D.V.M., an experienced lifelong horseman and a graduate of the University of Illinois College of Veterinary Medicine. As an equine medicine practitioner in California for 13 years, Dr. Byrd served as ex-officio member of the board of directors of the Pacific Coast Quarter Horse Racing Association where he also served as the organization’s official sales veterinarian. In addition, Dr. Byrd frequently officiated, as veterinarian for horse shows sponsored by the management of Orange County Fairgrounds in Costa Mesa, California. Dr. Byrd’s extensive experience with horses led him to observe how a horse’s health could impact performance leading to the founding of the specialist lab for equine fecal worm egg counts. Please visit to find out more about F.E.C.T. services available directly to the horse owner including; advice on equine fecal egg count testing; quick and easy purchase of test kits online; reporting and expert consultation services. Dr. Byrd enjoys sharing his wealth of knowledge of equine parasitology with horse owners from all walks of life, and is available to provide lectures/symposiums for your club, organization or event. Please contact Dr. Byrd via his website for rates and further information.

About Nikki Alvin-Smith: International and national published freelance writer and photographer in such world renowned publications such as The Chronicle of the Horse, Horse and Hound, Dressage and CT, Warmbloods Today, The Horseman’s Yankee Pedlar, Reiter, The Equine Journal, Spur, Hoofprints, Horsin’ Around, Horses All, Field & Stream, Western Horse and Gun, Pony Quarterly, Horses All Canada, Catskill Horse to name a few. Ghostwriting, blog services, PR/Marketing copy either direct with manufacturer or for agencies, copy editing and editor services also available. Nikki also produces catalog copy, white papers, e-books, corporate brochures and advertising copy for international corporations and PR/Marketing for celebrities.

As a Brit who has called the America home for the past 34 years, Nikki brings a unique perspective to the equestrian world. Nikki is also an accomplished Grand Prix dressage trainer/competitor, competing at international Grand Prix level to scores over 72% and is a highly sought clinician offering clinics worldwide. She has been a horse breeder/importer of warmblood and Baroque breeds for more than 25 years. Together with her husband Paul who is also a Grand Prix trainer, they run a private dressage breeding operation and training yard in the beautiful Catskill Mountains of New York. Please visit to learn more.

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