Lameness can be definitively diagnosed only by your veterinarian, but the detective work of the diagnosis is best performed as a team. A prognosis for a full and speedy recovery often corresponds with diagnosing problems as soon as possible, so the ability to spot problems early on is crucial.
Here, I'll give you five ways to detect lameness: (1) Look for nonspecific signs (physical and attitudinal changes); (2) look at the whole horse; (3) watch your horse move; (4) listen to his footfalls; (5) feel for under-saddle clues; (6) observe his feet.
6 Ways to Detect Lameness
Lameness Check #1: Look for Nonspecific Signs
Nonspecific signs don't tell you what's wrong with your horse, or even if it's a lameness issue. They do tell you that it's time to take action to figure things out. These nonspecific signs include:
Lameness Check #2: Look at the Whole Horse
When you decide something is bothering your horse, take time to look him over closely from head to toe. Observe him at rest in his stall and on turnout. Does he habitually point one front leg forward, or rest one hind leg more than the other? Does he stand with his elbows turned out? Does he stand with his toes or stifles rotated out behind? Does he stand with all four legs squarely perpendicular to the ground?
Starting at his head and ears, run your hands over your horse's whole body and down each leg. When you run your hands over certain areas, note if he shrinks away, flicks his skin, pins his ears, kicks, etc. Check for any obvious swelling or heat.
Observe your horse from the front, sides, and back when someone is at his head and he's standing squarely. Look for any differences in how well your horse is muscled from side to side. You'll often see smaller, less well-defined muscles if there's pain in the associated leg. Localized areas of muscle tension (muscles will feel hard) are also commonly found when a horse is hurting somewhere.
Check your horse's feet. When there are longstanding painful conditions in a front leg, the hoof on the painful side will often be smaller than the opposite front. When painful conditions involve the front or back legs, you may see shoes/hoof walls wear more quickly on the comfortable side than the sore one, and wear patterns may be different.
Lameness Check #3: Watch Your Horse Move
Watch your horse move in a circle, going both directions, first free of tack, then with tack but no rider, and finally tacked up with a rider.
Lameness tends to be exaggerated when a horse is moving in a circle and is easiest to spot at the trot. If the tack itself is bothering your horse, you may be able to see this difference in how nicely he moves with and without tack, especially if you're careful to tightly cinch the saddle.
Carrying a rider's weight can worsen a horse's lameness for several reasons: a saddle-fit problem may be made worse; more weight is put on the horse's front legs; the hind end has to work harder to move weight forward; it's difficult for the horse to make subtle changes in how he carries his weight.
First, observe your horse at the walk. Does he look relaxed? Is he swinging freely through his back, shoulders, and haunches, and is he taking smooth, generous strides? Are his head and neck moving in rhythm with the walk? Are his ears pricked? Does he bend smoothly on the circle in both directions? Does he move the same in both directions? Observe the same things at the trot in both directions.
Then tack up your horse, and note any differences with and without a rider. Horses that move in a stiff, wooden way are uncomfortable somewhere. After observing your horse move on a circle, watch him from directly in front, directly behind, and from the side at both the walk and trot. Watch him on both a soft and a hard surface. From the front, check to see if he has normal head movements and if he's landing evenly with his feet. Is he flexing his knees as high on both sides? Is he dragging a toe or stumbling?
From behind, watch your horse's rump to see if it rises and falls equally from left to right. Check to see if his back legs move forward in a straight line, swing in before the foot lands, or swing outward before landing. Does the hock flex smoothly or with an obvious "wobble"?
Watch from both sides. Does your horse bring his hind legs forward so the hooves land in (or even beyond) the print of his front hooves? If not, he's short striding behind. If only one leg is doing this, that's usually the painful one. If both legs are doing it, then he may be painful in both hind legs, or his pelvis, rump, or back.
Does your horse flex all joints evenly? Watch his fetlocks when each foot contacts the ground. Are they dropping the same amount on both sides? If not, he's not carrying his weight evenly from side to side. The fetlock that drops the most is taking more of the weight.
Compare the diagonal legs. A horse with a problem will often distribute more weight to the diagonal front or back leg. For example, a horse with pain in the left front may drop his ankle more in the right front and the right hind.
Lameness Check #4: Listen to Your Horse's Footfalls
Learn to "see with your ears." When moving your horse on a hard surface, you'll be able to hear subtle differences in how hard he's landing. Close your eyes, and concentrate on listening to the sound of his feet striking the ground. Each footfall should be as loud as the others, and you should hear an even rhythm.
You can hear many changes long before they can be seen. A softer sound will be heard when your horse isn't putting full weight on a leg, and the sound that follows will often be louder. If the rhythm — that is, the interval between footfalls — has a "skip" in it, with a loud ground contact following quickly after a softer sounding one, that's your horse hopping off a sore leg more quickly and shifting weight to another leg.
Lameness Check #5: Feel for Under-Saddle Clues
You can pick up important lameness clues when you're in the saddle. Do you feel a relaxed sway at the walk or does your horse's back feel rigid? If rigid, there's pain somewhere.
When you post the trot, does your horse throw you evenly on both diagonals? If not, the side with the weak thrust may be hurting. Does he take both canter leads evenly? If he's resisting a lead, suspect the hind leg on that side. Reluctance to turn to either direction suggests pain in a leg to the inside of that turn.
Lameness Check #6: Observe Your Horse's Feet
Watch how your horse stands and whether he habitually points a front foot. Also watch for frequent weight-shifting up front.
Look at the feet themselves. When one foot hurts more than the other, it'll often be smaller. It's also often more prone to thrush because the horse will try to avoid putting full weight on that foot. Bearing full weight on a foot forces manure and bedding out of the foot, keeping it cleaner. A narrower heel and frog are other signs of decreased weight bearing.
The back of the pastern should be smooth and tight, not puffy. Filling or edema can be caused either by inflammation in the foot or problems with the deep flexor tendon or the ligaments that insert on the back of the pastern.
Look for both diffuse swelling and defined pockets of swelling or fluid as you travel up each leg. Also pay attention to any areas that feel warmer than the rest of the leg and warmer than the same area on the opposite leg.
When you pick up your horse's legs for routine tasks, such as cleaning hooves, pay attention to whether he objects to lifting a particular leg for you. How well your horse stands for the farrier is an even better test of the same thing. When a horse doesn't want to pick up a leg, it's often because either the opposite one hurts to stand on, or the one you're asking for hurts when you flex a joint.
Eleanor M. Kellon, VMD, of Equine Nutritional Solutions in Ephrata, Pennsylvania, is an authority in equine nutrition and expert in the field of equine nutraceuticals. Her most recent book is Horse Journal Guide to Equine Supplements and Nutraceuticals (Globe Pequot Press).