Absorbine UltraShield EX vs Farnam Endure: Which Fly Spray Lasts Longer

Every summer in North Texas there is a week in June when the horse flies show up all at once, and every horse on the place starts stomping, swishing and rubbing its face on the fence. That week is when you find out whether the fly spray you bought in April was worth the shelf space. For the last few seasons I have kept two heavy-duty sprays in the tack room, Absorbine UltraShield EX and Farnam Endure, and I have used both of them on the same three horses, in the same pasture, through the same miserable heat. This is how they actually compare when you use them the way rodeo people use them, which is hard, often, and usually in a hurry.

Here is the short answer before the long one. If your horses live outside, sweat a lot, and get hauled to arenas where the flies are worse than at home, Absorbine UltraShield EX is the one I would buy. Farnam Endure is a good spray and I am not going to pretend otherwise, but in my barn the Absorbine held up longer between applications, especially on the days that mattered most. The rest of this piece explains why, and where Endure still earns a place.

	Absorbine UltraShield EX	Farnam Endure
Staying power on a sweaty horse	Held up best for me through hauling and hard runs	Good, but faded sooner after a heavy sweat
Coverage on a working horse	Light mist, easy to work into the coat	Slightly heavier mist, a bit more product per pass
Smell	Mild citronella note that fades quickly	Mild and pleasant, very similar
Coat feel after spraying	Leaves the hair clean, not sticky	Leaves a slight conditioned feel some people like
Best use	Turnout horses, hauling, arena days in heavy fly pressure	Barn horses and light fly pressure
Container	Quart bottle with trigger sprayer, refill sizes available	Quart bottle with trigger sprayer
My pick	Winner for long, hot rodeo weekends	Solid backup for easy days

How I Tested Them

I do not run a lab, so I will tell you exactly what I did and you can decide how much weight to give it. I split the horses between the two sprays for most of a summer and then swapped them so each horse spent time on each product. Biscuit, my 14-year-old sorrel gelding, got the bulk of the attention because he is the one I haul and run barrels on, and he sweats like a field hand in July. The other two mostly stood around in the pasture eating and complaining about the flies, which turned out to be a useful control group.

I sprayed in the morning after grooming, on a clean, dry coat, and I followed the label on both bottles for how much to use and how often. Then I simply paid attention. I watched how much stomping and tail work each horse did by mid-afternoon, how many flies were sitting on their legs and bellies when I went out to check water, and how they looked after a day at the arena. I kept notes on a calendar hanging in the tack room, because after twenty years of dispatching I do not trust my memory with anything I can write down.

I also paid attention to the days that tell you the most: the days Biscuit got hauled for an hour, warmed up, ran, cooled down, stood tied to the trailer in the sun, and then rode home. Those days wash a weak spray right off a horse. A spray that only works on a horse standing in the shade is not much use to anybody in this sport.

Where Absorbine UltraShield EX Wins

The difference showed up on the hard days. On a typical jackpot Saturday I would spray Biscuit at home before loading, and when the Absorbine was on him, the flies around the trailer at the arena mostly left him alone well into the afternoon. He still swished at them, because every horse does, but he was not stomping a hole in the ground or trying to rub his face on me while I tightened the cinch. By the time we loaded to go home, the spray was still doing its job on his legs and belly, which is where the biting flies concentrate.

The sweat resistance is the part I care about most. A rodeo horse sweats under the saddle pad, behind the elbows, and between the hind legs, and those are exactly the places flies go after once the spray breaks down. With the Absorbine, I could see the effect lasting through the sweat in a way I did not always get from Endure. On the hottest weekend of the summer I sprayed both a turnout horse and Biscuit in the morning, and Biscuit, after hauling and two runs, was in better shape at dark than I expected.

I also like how Absorbine UltraShield EX goes on. The mist is fine and even, so a quart goes further than you would think, and it does not leave the coat sticky or dull. That matters to me because I film runs at local rodeos now, and I see a lot of horses up close through a camera. A horse that has been sprayed with something greasy looks dusty and dull in the arena lights within an hour, because every bit of arena dirt sticks to it. Biscuit stayed clean looking on this spray, and so did the other two.

The last thing in its favor is consistency. Some sprays seem to work great one week and fall flat the next, which usually means the product is very sensitive to weather. The Absorbine behaved about the same through dry spells, humid weeks and a run of thunderstorms in August. When I am packing the trailer at five in the morning, I want one less thing to second guess.

A fly spray that only works on a horse standing in the shade is not much use to anybody who hauls to rodeos.

Where Farnam Endure Still Earns Its Keep

I want to be fair to Farnam Endure, because it is a good product and plenty of people I respect swear by it. On horses that mostly stood in the barn or in a shaded run, I could not see much difference between the two. Endure did its job, the horses were comfortable, and nobody was stomping. If your horses live in stalls with fans and only go out for an hour or two a day, you could use Endure all summer and be perfectly happy.

Endure also has a nice feel on the coat. It leaves the hair a little conditioned, which some people really like for show horses or for a horse with a dry, sun-bleached coat. A friend of mine who shows reining horses keeps it in her grooming box for exactly that reason. For a working rodeo horse that rolls in the dirt the minute you turn him loose, that conditioning does not mean much, but it is a real point in its favor for some barns.

Where Endure fell short for me was the long, hard day. After a heavy sweat, especially on hauling days, I noticed the flies coming back to Biscuit's legs and belly sooner than they did on the Absorbine days. It was not dramatic, and it was not every time, but it happened often enough that I started reaching for the other bottle on rodeo mornings. On a horse that has to stand tied to a trailer for six hours in a cloud of horse flies, a little extra staying power makes a real difference to how he behaves when it is his turn to run.

I would also say Endure seemed to go a little faster per application. That might be the way my sprayer delivered it, or it might be that I was using a bit more to feel like I had good coverage. Either way, a quart did not stretch quite as far for me as the Absorbine did, which adds up over a long fly season with three horses.

What Matters More Than Which Bottle You Buy

No spray works if it goes on wrong, and I see people at every rodeo making the same mistakes. Spray a clean, dry horse. If you spray over a coat caked with dried sweat and arena dust, the product sits on top of the dirt and wipes off the first time the horse rubs on something. A quick curry and brush before you spray makes any product last longer.

Get the spray where the flies actually bite. That means the legs, especially the inside of the forearms and the hocks, the belly, the girth area, the chest and the flanks. A lot of people mist the top line, which looks nice and does very little, because flies are not biting the top of the back nearly as much. For the face, never spray directly at the head. Spray a soft cloth or a gloved hand and wipe it carefully around the ears and jaw, staying well away from the eyes and nostrils.

Read the label and follow it, every time. These are insecticides, and the directions on the bottle are there for a reason. I keep both bottles on a high shelf in the tack room where my dogs and visiting grandkids cannot get into them, and I wash my hands after spraying. If you have a pregnant mare, a young foal or a horse with a skin problem, ask your vet before you use any of these products on them.

Finally, do not expect any spray to do the whole job alone. On my place a fly mask, a clean barn, and keeping the manure picked up all matter as much as what comes out of the bottle. The spray is one tool. On a hard summer, it is an important one, but it works best when everything else is pulling in the same direction.

One more thing worth saying about cost over a season, without getting into prices that change every month. The number that matters is not what a bottle costs on the shelf, it is how many good days of protection you get out of it per horse. A cheaper bottle that you have to reapply every afternoon ends up costing more, in product and in your time, than a bottle that carries a horse through a whole hauling day. When I added it up on my tack room calendar at the end of August, the Absorbine had needed fewer reapplications on Biscuit than the Endure had over a similar stretch, and that is the kind of math that decides what I buy next spring. Your numbers will depend on your horses, your weather and your flies, so keep your own notes for a few weeks and the answer usually becomes obvious.

Who Should Buy Which

Buy Absorbine UltraShield EX if your horses live outside or haul often, if they sweat hard during work, or if you spend long days at arenas where the fly pressure is heavy. It is the spray I trust on rodeo mornings, and it is the one I would pick if I could only keep one bottle in the trailer. For ranch families who are turning out a few horses on pasture and want something that holds up through a full Texas afternoon, it is the easy choice.

Buy Farnam Endure if your horses are mostly stalled, if the fly pressure where you live is moderate, or if you like a spray that leaves the coat feeling conditioned for showing. It is a perfectly good product, and there is nothing wrong with keeping a bottle of it for the easy days. In my barn, though, the Absorbine is the one that went home in the trailer, and it is the one I bought again when the bottle ran out.