Recent research has changed the way we view parasites and deworming in our horse population. For years, we did “rotational deworming” every 2 months, regardless of the type of horse, occupation, or environment. Now we know that this not the best way to prevent parasite problems. One staggering number has surfaced through this research – 20% of the horse population are responsible for 80% of the parasites!
The current recommendation from AAEP and Pineview Veterinary Hospital is an annual fecal to determine the parasite load on each horse. From there, horses are divided into three categories based on this fecal count – low, moderate, or high shedders (meaning shedding a low, moderate, or high number of parasites when they defecate). The recommendations then vary depending on which group your horse falls into, ranging from deworming 2-4 times per year.
We also know more about the parasites we are fighting against than ever before. For example, we know that there are two types of strongyles (the main type of parasite we deworm against). Large strongyles were the most common for years and in such abundance that they required deworming every 2 months. That constant deworming has almost eradicated large strongyles and left us to fight against the other type – small strongyles. These small strongyles act differently than the large and therefore need a different approach to our deworming protocols.
Zoetis has a great website to explain how this process works and offers examples of different types of horses and deworming schedules for different levels of shedding.
To schedule a visit with our veterinarians or speak with us about your current deworming program, please call our office.