Farnam SimpliFly Feed-Thru Fly Control Pellets Horse Supplement, 3.75-lb bucket

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About This Item

Details

  • Horse supplement features LarvaStop and diflubenzuron as the main active ingredients to prevent the formation of flies.
  • Helps prevent the development of house flies and stable flies in the manure of treated horses.
  • This supplement only affects your horse’s manure—it has no organophosphates and passes through your horse without being absorbed.
  • Veterinarian-recommended feed-thru solution is safe for horses of all ages and reduces fly populations when fed daily.
  • These easy-to-feed, palatable alfalfa pellets blend seamlessly with your horse’s grain—no need for messy sprays or complicated application routines.

Ingredient Information

Feeding Instructions

Learn More About Farnam From Our Team of Experts

About Farnam SimpliFly Feed Thru Fly Control

Break the Fly Lifecycle

Stop flies at the source with this easy-to-feed formula that keeps your horse’s manure from becoming a fly breeding ground. SimpliFly Feed-Thru Fly Control helps you easily reduce the fly population around your stable. Simply add the highly palatable pellets into your horse's daily feed to break the fly lifecycle right where it begins.

Feed-Through Fly Control

SimpliFly Feed-Thru Fly Control is an essential part of any fly management program for horses. The highly palatable pellets are easy to add to your horse’s daily feed, and they help significantly reduce the nearby population of house and stable flies.

Available in a Variety of Sizes

Both Repel-X Insecticide & Repellent and Repel-X pe Emulsifiable Fly Spray are available in a range of sizes to cater to different needs, whether for small-scale use on individual animals or larger operations that require bulk quantities.

Easy to Feed Alfalfa-Based Pellets

SimpliFly Feed-Thru Fly Control comes in a highly palatable pellet mixture that will blend right in with your horse's feed. Simply top-dress the product on grain or mix it in with your horse's total daily ration. The feed will pass through your horse unabsorbed and only affect the manure.

Easy Application

When SimpliFly Feed-Thru Fly Control is fed daily, house and stable flies are unable to develop in a horse’s manure. The fly lifecycle is interrupted and the fly population takes a direct hit, reducing the number of pests. The active ingredients in SimpliFly Feed-Thru Fly Control act in the horse's manure, not in the horse’s body, for a safe and simple fly control solution.

About Farnam

For over 75 years, Farnam has been a leader in equine care. Their mission has always been to strengthen the bond between horses and humans with simple, effective, and innovative solutions. Choose Farnam horse products to help make every moment of your time together happier, healthier, and more enjoyable.

Shop Farnam

Questions & Answers

10 Customer Questions


How many ounce(s) are in the plastic scooper?


Will this harm dogs or birds that eat horse manure?


Is this safe for Nigerian dwarf goats

Answer by ForefatherNov 12, 2025
It won't work for Ruminants, but it won't harm them if they eat it

How long does a bucket last?

Answer by ChewyOct 26, 2023
For one horse the 3.75 lb bucket has a 60-day supply, the 10 lb bucket has a 160-day supply, the 20 lb bucket has a 320-day supply, and the 50 lb bucket has an 800-day supply.

4.7
Rated 4.7 out of 5 stars
406 Ratings

179 Customer Reviews



Rated 1 out of 5 stars
By Karece on Jan 14, 2026

Maggots everywhere

I've been using this routinely year round and maybe it's a bad batch, because there were maggots everywhere yesterday. On the ground, in the muck barrels, and the

I've been using this routinely year round and maybe it's a bad batch, because there were maggots everywhere yesterday. On the ground, in the muck barrels, and the covered bins. It looked like a moving white carpet of larvae.


Rated 5 out of 5 stars
By Karen on Dec 6, 2025

Damaged product

I ordered 12 3.75 lb buckets of SimpliFly. One of them was shattered so the contents were all over the box. I still got what I paid for just had to scoop it up and

I ordered 12 3.75 lb buckets of SimpliFly. One of them was shattered so the contents were all over the box. I still got what I paid for just had to scoop it up and put it in another container. Otherwise I’m very pleased with Chewy and this product


Rated 5 out of 5 stars
By Wendy on Dec 12, 2025

This is an effective product

This was on sale so I bought 4 it's a bit pricey at the regular price but it saved on the amount of fly spray I had to use

This was on sale so I bought 4 it's a bit pricey at the regular price but it saved on the amount of fly spray I had to use


Rated 5 out of 5 stars
By Jennifer on Jun 20, 2025

Really Works

I was a little skeptical of this product when I first heard about it, but it really works. Not only does it reduce the buzzing around the manure, but it keeps the

I was a little skeptical of this product when I first heard about it, but it really works. Not only does it reduce the buzzing around the manure, but it keeps the flies off the horse as well. This is our second summer using SimpliFly. We start as soon as the weather starts to warm up and biting insects appear. After a couple weeks of use, my horse has no bug bites- and she is very sensitive to bug bites. Living in Central New York, we have a lot of biting insects. During the summer, she used to have bites all over, but especially in her ears and on her chest, and she would scratch like crazy. Now she is show ring ready with no bug bites.


Rated 5 out of 5 stars
By Debby on Oct 31, 2025

works great at a great price

I love how this product reduces flies but does not affect the horse! Thank you Chewy!

I love how this product reduces flies but does not affect the horse! Thank you Chewy!


Rated 5 out of 5 stars
By Penny on Sep 16, 2025

Fly control.

Easy to feed. Controls eggs in the manure. There are still flies but the number is reduced and in hot weather that's important.

Easy to feed. Controls eggs in the manure. There are still flies but the number is reduced and in hot weather that's important.


Rated 5 out of 5 stars
By Janet on Jun 26, 2025

It works

We have seven horses, and these Farnam SimpliFly Feed-Thru Fly Control Pellets have been the key to our success during this fly season in southeastern Arizona. Yes,

We have seven horses, and these Farnam SimpliFly Feed-Thru Fly Control Pellets have been the key to our success during this fly season in southeastern Arizona. Yes, we use SWAT and spray with Farnam WIPE, deworm regularly, put on fly masks, plus pick stalls (as usual), but this combination has meant legit fly control. I'm very happy and so are our horses.


Rated 2 out of 5 stars
By Susan on May 28, 2025

Does this stuff actually work

I’m going on to my 3rd or 4th year with this product. In the past I thought it cut down on the fly population but this year it seems to have no effect at all. I

I’m going on to my 3rd or 4th year with this product. In the past I thought it cut down on the fly population but this year it seems to have no effect at all. I started adding it to the grain in March but the flies are the worst I’ve ever seen and it’s still early in the season and the weather has been mild. I can’t imagine the flies being any worse if I discontinued this product. I have 12 horses and they live in large pastures.


Rated 5 out of 5 stars
By Karen on Jul 28, 2025

Less flies in the barn

I see all the baby flies devouring the manure, but hardly any adult flies. It works. Still have to use fly spray when they are out in the field, but not in the

I see all the baby flies devouring the manure, but hardly any adult flies. It works. Still have to use fly spray when they are out in the field, but not in the barn.


Rated 4 out of 5 stars
By Mischala on Aug 27, 2025

Works well

Use this every year. Just wish the price hadn’t nearly doubled from past years. May be forced to switch due to price

Use this every year. Just wish the price hadn’t nearly doubled from past years. May be forced to switch due to price