Mastering the Art of Deworming

The art of deworming horses has evolved over time. It wasn’t long ago that it was common practice to deworm your horse with any old deworming medication every 6 to 8 weeks in an effort to keep horses as parasite free as possible. However, this practice has proven to be ineffective and even counterproductive and can even overload the horse’s system with toxins which have their own detrimental effects. Below we will discuss the ideal way to go about determining, when and if to deworm a horse, which strategy is most effective as well as how to protect the precious liver from the harsh chemicals found in dewormers - a topic that is not discussed enough!

FEC first…

First and foremost, it is beneficial to perform fecal egg count (FEC) tests to determine the amount of eggs a particular horse may be shedding. Fecal testing is also beneficial as the test results will let the owners know which type of eggs are found and from there they may choose the best dewormer to target said parasites, or skip deworming for that cycle altogether if the egg count is low. Choosing to skip a deworming cycle if an egg count is low is helpful in prevention of overuse of deworming products which could lead the parasites building up a resistance to the medication used. Interestingly, resistance can happen as worms are able to develop genes that allow them to become essentially immune to dewormers which may ultimately make medications ineffective.This being said, there are some setbacks to relying on a FEC alone. For instance, the eggs of pinworms, bots or neck threadworms will never show up in a FEC test. Additionally, worms will not be detected if not in an active shed cycle and FEC tests will not reveal evidence of an existing population of ascarid and large strongyle migrating larvae, encysted small strongyles or immature adult worms within the horse. Given this information, a FEC will be more effective at different parts of the year, primarily spring and late fall when common parasites are in an active shed cycle.

Deworm strategically…

Strategic deworming refers to using the results of an FEC, selecting the correct dewormer appropriate for the highest egg count and then rotating different drug classes of dewormer during different parts of the year. This approach will prevent the parasites from building up a tolerance to a particular dewormer. If the same drug class is used over and over again, the parasites who survive the round of deworming will reproduce new generations who are more resistant to the overused dewormer which is also why the idea of deworming every 6-8 weeks is an outdated technique and counterproductive. Strategic deworming as refers to timing the FEC when common parasitic larvae begin to emerge, as discussed above, which is generally early spring and late fall. Timing is vital to get the best result as deworming at the proper time can thwart extensive egg laying that would perpetuate further infection for the rest of the year. In a nutshell, nip it in the budd while egg counts are highest to get the most out of your deworming efforts. Furthermore, try to select a product that kills larvae, adults and tapeworms and always give proper dosage based on the body weight of your horse.

Equine Deworming schedule Twenty Four Carrots
Deworming Schedule for Adult Horses

Support the liver!

Dewormers contain chemicals, there is no way to get around it. While these chemicals can kill parasites, they can also cause a great deal of stress on the liver and consequently the immune system entirely. When administering dewormers it is important to understand that heavy toxins are also being administered into the system which the liver must filter and process. These toxins are not natural to the horse and the liver must work harder than usual to process and filter the chemicals which can easily build up in the liver and the kidneys as well if the liver does a poor job of filtering the toxins. It is especially important that the liver is supported during times that it may be working harder, such as when chemical dewormers are administered. The best way to