This week, we’re talk vision and hearing changes in the senior horse.
Age-related vision changes are rare in horses, but I first noticed them in Aggie a few years ago. The biggest change was his tendency to spook at shadows, especially during sunrise or sunset hours. Other than an incident with a pig that shall not be named, Aggie didn’t spook. He had been on the show circuit since he was a 2-year-old and seen everything from helicopters to Ferris wheels, carried flags in rodeo parades and hauled a flailing news reporter on LIVE TV. But now he has trouble telling the difference between a very dark shadow and a hole.
My veterinarian cleared him of maladies such as cataracts, corneal ulcers and moon blindness, so I assume the vision loss is mild or perhaps he’s just a little more far-sighted nowadays. I have wondered if his problem stems from living in the deserts of West Texas most of his life. The sand is as blinding as snow in that area.
My simple solution was to ride Aggie in the late morning or early afternoon depending on the season. He seems to only have trouble with high contrast, light and dark areas, so avoiding very early and very late rides keeps him away from shadows.
The interesting thing my veterinarian told me is that most horses will try to mask vision loss, sticking to familiar routes and routines by memory. As a prey animal, hiding their “impairment” would certainly be their first instinct.
He also taught me two quick vision tests that anyone can do at home. You’ll need a halter and lead rope, small towel, tape, a handful of cotton balls and a bale of hay.
Vision Test #1
Step 1: Halter your horse and tape the small towel on the halter to cover one eye. Secure it with tape, careful not to put the tape directly on your horse’s skin.
Step 2: In a well-lit area, have someone hold your horse while you stand 3 feet away on the side of the uncovered eye. Gently toss 3 cotton balls so they bounce gently off your horse’s face between the eye and muzzle.
Step 3: Did he flinch before the first cotton ball touched him? Did he try to avoid the second or watch the third? If all your answers are no, your horse could have vision problems.
Step 4: Repeat with the other eye covered.
Vision Test #2
Step 1: With one eye covered, lead your horse on a loose lead at a quick walk toward a bale of hay 15 to 20 feet ahead.
Step 2: Does he try to avoid hitting the bale? If the answer is no, your horse could have a vision problem.
Step 3: Repeat with the other eye covered.
Aggie hasn’t shown any signs of hearing loss, but here’s a quick test for that as well. You’ll need “noisy” objects, such as plastic bag and a dog-training whistle. The whistle tests for hearing loss of high-frequency sounds. You’ll need to find a quiet place for the test away from road noise, wind or barn traffic.
Hearing Test #1
Step #1: Remove any feed from the test area. Chewing will affect the test.
Step #2: Stand 10 feet behind your horse and remain there until he ignores you.
Step #3: Moving as little as possible (you don’t want to have a visual response) start making noise.
Step #4: Wait one minute between each sound so the horse won’t discover the sounds are coming from you.
Step #5: Does he flick an ear towards you? If he doesn’t react to the whistle, he might have high-frequency hearing loss. If he doesn’t react to the plastic bags, he might have profound hearing loss and you should consult your veterinarian.
The veterinarian will first check for simple causes of hearing loss such as ticks, ear mites and ear infections. Unfortunately, there is no cure for age-related hearing loss. For more about a horse’s sense of hearing, check out this article from the Horse Nation archives.
Next week, we’ll discuss stretches to keep your senior horse limber.