Use these tips to help choose the right fly mask style and fit to
give your horse effective bug-season protection.
Horse Fly Mask Selection, Fit, Care Tips
By Amy Anderson with Sandra Cooke
Your horse's head is a vulnerable target during bug season. Face
flies seeking mucous-membrane moisture irritate his eyes and can
trigger allergies or infections. Biting flies attack the thin,
tender skin, sometimes working out of sight under his jaw.
Voracious gnats creep into his ears and leave crusty scabs and
discomfort behind. Fly repellent, which helps you keep insects
away from most of your horse's body, is a challenge to apply to
his head and ears for full protection.
An alternative strategy is a fly mask. Here's what it can do, if
it fits well and is clean and in good shape:
Allows your horse to see out while face flies can't get in to
irritate his eyes.
Keeps gnats out of his ears (if style includes ear coverings),
always a plus but especially beneficial if you clip his ears for
Protects sun-sensitive eyes and skin (such as pink skin under
large white facial markings) from harmful rays. Some designs come
with extended muzzle for extra coverage.
Fly Mask Tips
• Not sure which size mask will fit your horse? Contact the
manufacturer (website email links are useful) and ask which of
his head measurements they need to determine his size.
• For extra protection at the height of bug season, before
putting your horse's fly mask on wipe fly repellent (sprayed on a
soft cloth) under his eyes, on his muzzle, around his ears, and
under his jaw.
• Make sure to always have a clean mask handy by rotating two fly
masks, giving yourself more time to wash one while the other is
Find the Mask that Fits
Here are the critical points to check for fit:
Muzzle: The mask's lower edge needs to reach one to one and a
half inches below the bottom of your horse's cheekbone; otherwise
the cheekbone creates a gap under the edge of the mask through
which flies can easily pass. A mask whose lower edge ends on, not
below, the cheekbone can cause rubs as well. Greater facial
coverage reduces the amount of skin on which face flies (which
will hang around even if they can't get at his eyes) can crawl,
and protects more facial skin from sunlight.
The edge of the mask doesn't need to be so snug against the skin
that an insect can't creep under it; you should be able to slip
your finger easily between the mask and your horse's muzzle.
Elastic around the lower edge of the mask is useful because it
provides some "give" for jaw movement when your horse is grazing
outside. (Flies that encounter the edge of the mask don't try to
push underneath it; they typically crawl up over the mask on the
Throatlatch: This area can get uncomfortably tight when your
horse picks his head up unless you allow a couple of fingers'
width between the mask edge and his throatlatch. As with the
muzzle, you should also be able to slide your finger easily
between the edge of the mask and his skin at the side of his
head. In addition to chafing and binding, a too-tight throatlatch
fastened with Velcro™ or other types of hook-and-loop straps used
on most fly masks will tend to come undone from the constant
Ears: If your horse is sensitive about having his ears handled,
he may be less bothered by a fly mask with ear protectors that
slip softly over his ears than by a design with holes through
which his ears must be threaded. Check the ear area to be sure
the mask's ear coverings or ear-holes are aligned with your
horse's ears and are roomy enough for his ear size. If the mask
doesn't fit him well here--the openings are spaced too closely or
too wide apart for his ear placement--he's more likely to get
rubs from the edges of ear holes than from ear coverings.
Eyes: You've saved the most important check for last. A fly mask
becomes an irritant instead of a protector if it fits too closely
around the eye, where the mask mesh can cause painful abrasions
to the eyeball. The fabric of the mask needs to stand out well
away from the eye, giving total clearance to the eyelashes. When
you've fastened the mask with the correct amount of snugness and
checked for fit elsewhere, look carefully from the front, side
and rear of your horse's head to be sure it clears the eye from
every angle whether his head is lowered or raised.
If using a mask made of stiffer mesh with sewn-in darts shaping
the fabric around the eye, make sure the widest, roomiest part of
the mask is actually located over your horse's eye rather than
higher up his face; some masks are simply too short between the
ear area and the eye shaping. (In extreme cases where the mask
fits much too close to your horse's eye, it's sometimes possible
to see his eyelashes poking through the mesh--take the mask off
Wash it! Wash it every day, if necessary. Unless your horse's fly
mask is clean, it will shed flecks of dirt into his eyes or
irritate his skin through contact with sweat- and mud-caked
fleece edging. It's a quick, simple matter to dunk a mask into a
bucket of water with a squirt of mild liquid soap and slosh it
around (gently) until all the dirt has loosened and washed away.
Pay special attention to fleece edging, scrubbing it between your
fingers if needed. When the edging is very soiled, use a mild
Betadine solution (the color of weak tea) instead of soapy water,
for disinfection. (Hook-and-loop closure straps can become matted
with bits of trash or hair, but avoid hard scrubbing, which can
damage their ability to grip. Instead use a stiff grooming brush
or a dog's wire "slicker" brush on matted straps when they're
dry.) When dirt is washed off, rinse the mask very thoroughly in
several changes of fresh water until all traces of soap or
Betadine are gone, then shake off excess water. The mask
air-dries in a couple of hours (don't put in the clothes dryer).
Check for damage. Ripped or worn areas of the mask can let
insects in and stray fibers from the mesh may irritate your
horse, especially if the damaged part is near his eyes (as can
happen if he snags it on something while having a good roll).
It's also common for wear and tear to show up in seams that
connect ear coverings. Masks are difficult to repair
satisfactorily and it's a good policy to replace them when
damaged. Recent improvements in design and materials have
increased durability and it's not unusual for a fly mask to last
a season or more.
Amy Anderson is barn manager for the Katonah, N.Y., home base of
Andre Dignelli's "A" circuit powerhouse Heritage Farm, where she
supervises the care of 65 to 70 horses as well as training and
This story originally appeared in the June 2004 issue of
Practical Horseman magazine.
Just the Coolest Plush Stuffed Horses