Horse Wormers
Internal parasites are one of the leading causes of colic, weight loss, and poor performance in horses — and they are largely invisible until the damage is done. A consistent, strategic deworming program based on your horse's actual needs is one of the most impactful things you can do for their long-term health.
What Horse Owners Are Actually Asking About Deworming
How often does my horse actually need to be dewormed?
The blanket "deworm every 8 weeks" recommendation has been replaced by fecal egg count-based programs in most modern equine veterinary practice. Horses vary dramatically in parasite shedding — some are high shedders that need more frequent treatment; others maintain low egg counts and need less. The modern standard: work with your vet to establish a baseline fecal egg count, then create a personalized program. Twice-yearly strategic deworming (spring and fall) is still widely used as a minimum for all horses regardless of counts.
Which dewormer should I use — ivermectin or moxidectin?
Ivermectin is effective against most common equine parasites including large and small strongyles, roundworms, pinworms, and bots. Moxidectin covers a similar spectrum but is more effective against encysted small strongyle larvae — making it particularly valuable for the fall deworming when targeting overwintering larvae. Rotating between active ingredients prevents resistance from developing. Durvet and Merial offer both formulations in the paste format most horses accept readily.
What is the difference between paste and gel dewormers?
Paste dewormers are the most common format — they come in a pre-measured syringe, dosing is determined by body weight using the dial on the plunger, and administration is straightforward for most horses. Gel dewormers have a slightly different consistency some horses tolerate better than paste. Both deliver the same active ingredients at the same effectiveness. The key variable is accurate weight estimation — over or underdosing is the most common deworming mistake.
My horse spits out their dewormer — how do I actually get it into them?
The most reliable technique: administer the dewormer paste to the side of the mouth between the teeth and cheek rather than straight back on the tongue. Keep the horse's head elevated for 10-15 seconds after dosing. Rinse the syringe with water before use so the medication slides out more cleanly. For horses that are very resistant, apple sauce or a small amount of molasses on the syringe tip can make the experience more positive over time.
Building a Smart Deworming Program
- Get a fecal egg count: Before creating any deworming schedule, establish your horse's baseline with your vet. It takes the guesswork out entirely.
- Rotate active ingredients: Never use the same active ingredient back-to-back. Resistance develops when parasites are repeatedly exposed to the same chemical.
- Dose by weight, not by size: Use a weight tape or scale to estimate body weight accurately. Underdosing is one of the primary drivers of resistance.
- Include a bot treatment in fall: Bot flies are most active in summer — their larvae overwinter in the stomach. A fall deworming treatment that covers bots (ivermectin or moxidectin) is particularly important.
Brands Horse Owners Trust
Durvet and Merial are the most widely used equine dewormer brands in North America — their ivermectin and moxidectin formulations are the benchmark for reliability, palatability, and consistent dosing accuracy. Both brands are available in single-dose and multi-pack formats for multi-horse operations.
At Hooves and Paws, horse wormers are stocked year-round for single-horse owners and large operations alike. Fast shipping on ivermectin, moxidectin, and bot treatment formulations.
