6 Best Fly Control Feed Options For Horses Old Farmers Swear By
Control flies from the inside out. Discover 6 feed-through options for horses, from traditional garlic to modern supplements, trusted by seasoned farmers.
There’s nothing more frustrating than watching your horses spend their summer stomping, swishing, and shaking their heads instead of grazing peacefully. You can douse them in fly spray every morning, but by noon, the pests are back with a vengeance. This is where a smarter, more strategic approach comes in—tackling flies from the inside out with feed-through fly control.
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How Feed-Through Fly Control Works for Horses
Let’s get one thing straight: feed-through fly control doesn’t repel flies from your horse’s body. It’s not a force field. Instead, it works by breaking the fly life cycle right where it starts—in the manure pile.
The active ingredients in these supplements are insect growth regulators (IGRs) or larvicides. They pass through the horse’s digestive system completely undigested and are excreted in the manure. When flies lay their eggs in that treated manure, the larvicide prevents the larvae from developing into adult flies. It’s a targeted strike against the next generation.
The key to making this work is consistency and herd-wide application. Every horse on your property needs to be on the supplement. If even one horse is untreated, their manure becomes a fly-breeding sanctuary, undermining your entire effort. You have to start feeding it before the first flies of spring appear and continue until after the first hard frost.
Farnam SimpliFly with LarvaStop: A Top Choice
When you want a reliable, no-fuss option that just plain works, Farnam’s SimpliFly is hard to beat. It uses an ingredient called diflubenzuron, an insect growth regulator that specifically targets the fly larvae’s ability to form an exoskeleton. Think of it as preventing the fly from ever growing its armor.
This product is highly palatable, which is a huge plus. Even picky eaters usually clean it up without any fuss, making your daily chores that much easier. You just top-dress it on their regular grain ration. It’s a modern, effective solution that has become a staple in many feed rooms for good reason.
Because it’s so targeted, it doesn’t harm beneficial insects like dung beetles, which are crucial for healthy pastures. It’s a smart, focused approach that interrupts the pest cycle without disrupting the helpful parts of your farm’s ecosystem. For a straightforward, scientifically-backed solution, this is a top contender.
Equitrol II: Time-Tested Feed-Thru Control
Equitrol II is one of the old guards of feed-through fly control, and it has stuck around because it’s effective. Like SimpliFly, it uses diflubenzuron to halt the development of fly larvae in manure. Its long-standing presence in the market means it has a track record you can trust.
Many horse owners who have used it for years swear by its consistency. It’s a familiar name and a reliable choice, especially if you’re looking for something that has been proven season after season on farms just like yours. There’s a certain peace of mind that comes with using a product that has been a go-to for decades.
The formulation is designed for easy feeding, and it provides a simple, direct way to manage fly populations at their source. If you value a long history of performance and a no-frills approach, Equitrol II is a solid choice that has earned its reputation.
Solitude IGR for Potent Larvicide Action
Solitude IGR is another heavy-hitter in the feed-through world, often recommended by veterinarians. Its active ingredient is cyromazine, which is a different class of insect growth regulator than the one found in SimpliFly or Equitrol. This is a key advantage if you’re concerned about potential insect resistance.
By using a different mode of action, Solitude IGR provides a powerful alternative. It disrupts the molting process of fly larvae, effectively stopping their development dead in its tracks. The pellets are known for being extremely palatable, which is a critical factor for ensuring every horse gets its daily dose.
This is a premium option, and its price can reflect that. However, for barns with heavy fly pressure or for owners who want the most potent larvicide available, many find the investment worthwhile. It’s a targeted, powerful tool for serious fly control.
SmartBug-Off Pellets: An All-Natural Defense
For those who prefer to avoid chemical larvicides, SmartBug-Off offers a completely different strategy. This supplement uses a blend of natural ingredients like garlic, brewer’s yeast, and apple cider vinegar. The goal isn’t to kill larvae in the manure, but to make the horse itself less appealing to flies.
The theory is that these ingredients are excreted through the skin and breath, creating a scent that pests find repulsive. It also contains diatomaceous earth, which may help deter larval development, though its primary function is as a natural repellent. This approach is about defense, not offense.
Get 4lbs of HARRIS Food Grade Diatomaceous Earth, a natural product with no additives, OMRI listed for organic use. Includes a powder duster for easy application.
Let’s be realistic: an all-natural repellent is rarely going to be as potent as a chemical larvicide. Its effectiveness can vary significantly from horse to horse. However, for owners committed to a chemical-free program, or for horses in areas with lower fly pressure, it’s an excellent way to provide some relief without synthetic ingredients.
Absorbine UltraShield Fly Control Supplement
Absorbine takes a multi-faceted approach with their UltraShield supplement. It combines the proven larvicide diflubenzuron with a host of other beneficial ingredients. This makes it more than just a fly control product; it’s a comprehensive wellness supplement.
In addition to stopping the fly life cycle, this formula includes omega-3 fatty acids, biotin, and other nutrients to support healthy skin and a shiny coat. The idea is to build a healthier horse from the inside out, making them naturally more resilient to skin irritations caused by bug bites. It’s a two-pronged attack: kill the next generation of flies and support the horse’s own defenses.
This is a great option if you’re already feeding a skin and coat supplement. It allows you to consolidate your feed program into one product, potentially saving you time and money. It’s for the owner who wants to address fly control and nutritional support in a single scoop.
Using Garlic Powder: An Old Farmer’s Trick
You can’t talk about feed-through fly control without mentioning good old-fashioned garlic powder. For generations, farmers have added a spoonful of garlic to the feed bucket, believing its strong sulfur compounds make horses less tasty to flies. It’s the original, all-natural insect deterrent.
The idea is simple: the pungent compounds are released through the horse’s skin, creating a natural bug-repellent aura. Many people report seeing a noticeable decrease in the number of flies landing on their horses. It’s inexpensive, easy to find, and simple to use.
However, garlic is a repellent, not a larvicide. It won’t do anything to stop the fly life cycle in your manure pile. Its effectiveness is also highly anecdotal and can depend on the horse, the dose, and the type of flies you’re dealing with. It’s a worthy trick to have up your sleeve, but it’s best used as part of a larger plan, not as your sole line of defense.
Integrating Feed-Throughs with Pasture Care
No feed-through supplement is a magic bullet. The most effective fly control program combines an internal strategy with smart external management. You can’t just toss a supplement in the feed bin and expect your farm to become a fly-free paradise.
Your first priority should be manure management. Regularly clean stalls and paddocks. If you can, compost your manure pile properly; the heat generated during composting will kill fly eggs and larvae. Dragging your pastures on hot, dry days can also help by breaking up manure piles and exposing larvae to the sun.
Next, eliminate standing water. Check for leaky troughs, clogged gutters, and old tires or buckets that collect rainwater. These are prime breeding grounds for both flies and mosquitoes. By combining a quality feed-through with diligent pasture care and strategically placed fly traps, you create a comprehensive defense that will give your horses the peaceful summer they deserve.
Ultimately, winning the war on flies requires a multi-front attack. Choosing the right feed-through is a crucial first step, but it’s most powerful when backed by good old-fashioned farm hygiene. Whether you opt for a potent larvicide or an all-natural repellent, integrating it into a thoughtful management plan is the real secret to a quieter, more comfortable season for you and your horses.
