One of Soulful Equine’s product reviews is on a company called Horsemen’s Laboratory and on the service they provide for helping you manage parasites in your horse.
That review is not complete unless I discuss the subject of parasite resistance in horses as it relates to chemical deworming.
Parasite resistance in horses has been a problem for many years.
The average horse owner may not be aware of the impact this particular problem is beginning to have on the horse industry.
Although some of the first reports of resistance to deworming drugs date back to the early 1960s, it has started to become an even greater concern.
This concern over parasite resistance is actually growing worldwide and is not something to take lightly.
Denmark’s Approach to Parasites in Horses
I came across an interesting article and discovered that in 1999 Denmark enforced a law where horse owners could no longer purchase chemical dewormers over the counter. Side Note: In Denmark, they call chemical dewormers “drenches”.
This came about because of the growing concern over resistance issues. In reality, many horse owners are using dewormers inappropriately, which is causing a rapid growth of parasite resistance to these drugs.
Denmark’s solution to this was to take it out of the hands of the horse owner and make it a prescription only drug. It placed worm control into the hands of the veterinarians, who have to be satisfied that a horse’s worm burden is great enough to where it would require chemical deworming.
There may come a time, as it has in Denmark, when we can no longer purchase over the counter dewormers in the United States. I believe there are pros and cons to that decision. I will not go into that in this article, however, keep in mind that this could possibly be another reason for concern.
Parasite Resistance Should Be Taken Seriously
The intent of this article is to shed light on the growing issue of parasite resistance and to stress that it should be taken seriously.
Parasitologists agree that horse owners need to have a strategy for deworming which includes monitoring whether their program is working and if their horse even needs to be dewormed. This can be done using fecal egg counts.
Rotating chemical dewormers is no longer the answer to the worm resistance problem that has been created.
The misconception is that all horses have worms. Something that is becoming more and more common is checking your horse for worms first rather than blindly deworming them not knowing their worm burden.
All horses are exposed to worms but not all have worms, or if they do, the worm burden may be minimal.
If we do fecal exams and only treat our horses if they need it, then we are contributing to the longevity of our horse as well as minimizing the amount of chemicals we put into our environment. We are also minimizing our contribution to the worm resistance problem.
Completely eliminating parasites in our horses is not realistic, but by conducting fecal egg counts you can build a picture of each horse’s sensitivity to parasites and determine the effectiveness of the program you have in place. That program may be either a chemical, holistic/natural program or a combination of the two. No matter what the program, it is important to know if it is working.
No chemical dewormer is 100% effective, therefore, it is important to check your horse by doing a fecal egg count.
It is important to not treat all your horses the same. You must tailor a program to each individual horse. A big misconception is that if one horse in the herd has a high worm burden then all the horses in that herd must be infested.
I can tell you for a fact that is not a true statement and I have witnessed it in my own herd. Therefore, be sure to not give into the peer pressure of deworming all your horses just because one may need it. Keep in mind that you are part of the resistance problem every time you make the decision to chemically deworm your horse.
If treatment is necessary, the range of time between each can vary. Sometimes treatment is not needed at all. What is appropriate for one farm or horse may not apply to another.
Patterns of resistance can vary from country to country, state to state, and even between properties. It just depends.
Many owners simply decide to stick to a routine of chemically deworming their horse(s) without using fecal egg count tests. This is the mentality that continues to contribute to the problem of parasite resistance.
This thought process may also put horses at risk who do not need drugs to fight off worms/parasites. They may already have their own natural resistance built up.
Say Goodbye To Old Deworming Standards
Although it has been drilled into our heads that we should chemically deworm our horse every 6-8 weeks, it is time to say goodbye to that approach. This is an old way of thinking that needs to change.
What if your horse didn’t have worms and you still gave her a chemical dewormer every 6-8 weeks? Do you think it’s wise to continue to give her chemicals when it is not needed? As a holistically minded individual, I believe it is not only unnecessary but irresponsible when it comes to your horse’s overall well being and longevity, not to mention what it does to the environment.
Your Best Defense
Most sports have a saying that “Your best defense is a strong offense.” The offense I use in the war on worms is a GREAT, not just good, immune system. In other words, I create a good neighborhood in my horse and I create super immunity. A strong immune system starts in the gut. Therefore, you must have a healthy gut in order to have a great immune system.
The funny thing about that is the more we chemically deworm our horses, the more we are compromising both the gut and the immune system.
The message I would like to stress is that a healthy immune system is important when it comes to keeping the numbers of internal parasites low. – Stephanie Krahl
What Are The Fecal Egg Count Ranges?
Fecal egg counts will determine the number of eggs per gram (EPG) in the manure.
This eggs-per-gram number is a standard measure and, depending on the number, it will determine if your horse is carrying a low, moderate or high worm burden.
I personally follow the ranges below when determining the worm burden in my own horses.
- Unimportant (50 EPG or less)
- Low (75 – 225 EPG)
- Moderate (250 – 650 EPG)
- High (650+ EPG)
My Rule Of Thumb
I always ask myself this question before I take any kind of action with my horses … “Will this action compromise my horse’s immune system?” If the answer is yes, I will usually do my best to find an alternative. If there is not an alternative that works, then I do my best to find a way to minimize compromising their immune systems or I give them extra nutritional support during those times.
Just for the record, the list (Note: this is not a complete list) of items below can compromise a horse’s immune system:
- Over vaccinating
- Use of chemical dewormers
- Use of chemical fly sprays
- Stress during travel or change in environment
- Any feed or hay produced using any kind of chemical
- Processed supplements and feed stuffs
In closing I would like to leave you with a list of items to consider when it comes to fighting worm resistance:
- Check your horses for parasites regularly using fecal egg counts
- The misconception is that all horses have worms so we continue to deworm without really knowing our horse’s worm burden, that is if they even have one.
- Rotating chemical wormers is no longer the answer to the worm resistance problem that has been created.
- All horses are exposed to worms but not all have a worm burden, or if they do, the worm burden may be minimal.
- Using chemical dewormers on a regular 6-8 week schedule could be harming your horse (even more than the worms themselves) by weakening her immune system and her natural resistance against them.
- Over use of chemical dewormers may also contribute to laminitis which may lead to founder
- Programs that chemically deworm all horses frequently, no matter if they have worms or not, are contributing to the worm resistance issues existing today as well as to pollution in the environment.
- Put paddock management techniques in place that minimize exposure to parasites
Keeep it soulful,
Photo Credit – original photo modified in size and to include the Soulful Equine name and URL
Resources For More Information
- Horsemen’s Laboratory has made it simple to determine if your horse really has worms! They have put together kits that include a sturdy container, plastic bag and a prepaid self-addressed envelope.
- Great Information from Dr. Dan Moore, The Natural Vet, on Deworming – Note: I would recommend watching each video and listening to each audio he has available. It will give you a different view on deworming.
- Check out the awesome article in the April 2010 issue of Horse Illustrated titled “Fighting The Resistance” by Cynthia McFarland
- More Information On Parasitism