60 FEBRUARY 2016 | HorseIllustrated.com
won’t indicate that he is bothered, but more severe
allergic reactions can be extremely itchy or worsen
to cause swelling of your horse’s airways. Therefore
you should also examine your horse’s breathing.
2. If your horse appears content, think back to what
your horse has been exposed to in the past 12 to
24 hours. Has there been any new medication,
ointment, feed, supplement, tack, bug spray,
shampoo, or even a change in bedding?
3. Many mild cases of hives will go away on their
own. If you don’t see resolution in the skin
condition within six to eight hours, or if you
notice that things are getting worse, call your
veterinarian. Administration of a corticosteroid
such as prednisolone usually helps eliminate the
immediate itchiness. Some detective work may
help you identify the cause so as to prevent hives
in the future.
Sweet itch is a common seasonal skin disease that
is actually an allergy to biting midges, also called
“no-see-ums.” This condition most commonly occurs
along the horse’s topline, around the mane and tail, as
well as on the face and ears. It manifests in a range of
signs that include
scaly patches of
itchy skin, scab
hair loss in
If you see your horse becoming itchy and miserable
in the summer, here’s what to do:
1. Treat the immediate skin reaction. This normally
involves a veterinarian’s prescription for oral
steroids for a short time. These drugs will help
reduce skin inflammation and prevent itchiness.
Preventing your horse from perpetually itching will
then allow the skin to begin to heal.
2. Reduce your horse’s exposure to biting midges.
Since these insects feed primarily at night, stalling
your horse during this time with a fan can help
decrease the number of bites. Flysheets and
spraying with an insecticide containing pyrethrin
will also help.
3. Establish an insect control plan at the barn to
help your horse in the future. This includes proper
manure management, adequate ventilation in the
barn, and minimizing stagnant water.
Sarcoids and melanoma are two of the most commonly
encountered equine skin cancers. Both types of cancer
can range from fairly benign to invasive and destructive.
While most sarcoids appear on the head, neck, or legs
of a horse, melanoma occurs most commonly in gray
horses around the perineum and elsewhere underneath
the tail. Sarcoids can come in a variety of shapes and
sizes, while melanoma is usually fairly uniform and
distinct as a firm nodule or group of nodules.
Treatments for equine skin cancer vary based on
what type of cancer is present, its location, and
how invasive it is. However, in general terms, here
are some guidelines:
1. If you have a gray horse, make checking under
the tail a regular part of your grooming routine.
This way, you have greater chance of noticing
something unusual earlier.
2. For all types of horses, take the time during
grooming to note any odd lumps or bumps
anywhere on your horse’s body. If you notice
something that appears painful, oozing, changing
size, or is otherwise irritating your horse or
concerns you, call your vet to come look at it. HI
ANNA O’BRIEN, DVM, is a large-animal ambulatory
veterinarian in central Maryland. Her practice tackles
anything equine in nature, from Miniature Horses to zebras at
the local zoo, with a few cows, goats, sheep, pigs, llamas, and
alpacas thrown in for good measure.
Melanoma occurs most frequently in gray horses.
Check underneath the tail regularly during
grooming, as this is the most common location.