How to Spot Lameness in a Horse: A Practical Owner's Guide

Reviewed by Dr. Khurrum Shahzad Khosa, DVM

Lameness is one of the most common reasons horses require veterinary attention. Being able to detect it early — before a subtle change in gait has been worked through and progressed into a more established injury — is one of the most valuable skills an owner can develop. A horse detected as lame at Grade 1 that is rested promptly has a far better prognosis than the same horse that has been ridden for several more weeks while the owner dismissed the signs as "just stiffness."

Equally important is the ability to describe what you have seen clearly and accurately to your vet. Knowing which limb appears affected, when you first noticed it, whether it is better or worse on hard or soft ground, better or worse after warming up, and whether there are any associated physical findings such as heat or swelling helps your vet enormously before they arrive — and in some cases allows them to advise on management over the phone before an examination is possible.

The AAEP Lameness Grading Scale

The American Association of Equine Practitioners (AAEP) lameness grading scale is the standard system used in equine practice internationally. It runs from 0 to 5:

Grade 0: No lameness detected under any circumstances.

Grade 1: Lameness difficult to observe and is not consistently apparent, regardless of circumstances (weight-carrying, circling, inclines, hard surfaces).

Grade 2: Lameness difficult to observe at a walk or trotting in a straight line but consistently apparent under certain circumstances (circling, inclines, hard surfaces).

Grade 3: Lameness consistently observed at a trot under all circumstances.

Grade 4: Obvious lameness, marked nodding, hitching, or shortened stride at a walk.

Grade 5: Minimal weight-bearing in motion and/or at rest; complete loss of function in the affected limb.

Grade 3 or above warrants prompt veterinary attention. Grades 1–2 should be monitored carefully and if not improving after 24–48 hours of box rest, veterinary assessment is warranted.

Assessing Lameness at Walk

Begin your assessment by watching the horse walk on a firm, level surface. Have a helper lead the horse at a steady walk while you observe from the side and then from in front and behind. Grade 4–5 lameness will be immediately obvious at walk — the horse will take visibly shorter, guarded steps with the affected limb, and may show a pronounced head nod even at walk for severe forelimb lameness.

Subtle lameness at Grades 1–2 is often entirely invisible at walk. Do not be reassured by a horse walking normally if it has been showing signs of discomfort — move on to trot assessment before concluding the horse is sound.

Assessing Lameness at Trot — The Head Nod Test

Trot is the most useful pace for observing lameness. The symmetrical, two-beat diagonal gait makes asymmetry easier to detect than at walk or canter. Have your helper trot the horse away from you in a straight line on firm, flat ground, then trot back toward you. Observe from behind as the horse moves away, and from in front as it approaches. Use a hard surface: trotting on soft ground can mask significant lameness.

For forelimb lameness, watch the horse's head. The principle is this: when a horse is lame on a front leg, it instinctively reduces the load on that leg by raising its head as the painful limb bears weight — and drops its head (nods) as the sound leg hits the ground and accepts the greater proportion of body weight. The result is a visible head nod. The head nods DOWN when the SOUND leg strikes, and RISES when the LAME leg bears weight. The memory aid is "down on sound."

The magnitude of the nod tells you about severity: a subtle, barely visible nod is Grade 1–2; a pronounced, rhythmic nodding is Grade 3–4. A very mild nod is easy to miss, particularly in horses with long necks. Video the horse at trot on your phone and watch it back in slow motion — this can reveal asymmetry invisible to the naked eye in real time.

Assessing Hindlimb Lameness — The Hip Hike

Hindlimb lameness is assessed primarily from behind the horse as it trots away. Watch the croup and hips: in a sound horse, the movement of both hips is symmetrical. In a hindlimb lame horse, the hip on the lame side rises more — this is called the hip hike. The lame hind leg pushes off less powerfully than the sound limb, so the pelvis on the lame side is elevated rather than being driven down and forward by strong gluteal and hindlimb propulsion.

Hindlimb lameness can be more challenging to assess than forelimb, and significant experience is needed to reliably detect mild hindlimb lameness. Do not be discouraged if you find it difficult: even experienced equine vets can find hindlimb lameness assessment challenging, which is why they use additional tools including nerve blocks and imaging. What matters as an owner is noticing that something looks asymmetric and calling your vet to investigate properly.

Circling to Exaggerate Lameness

Trotting a horse in a small circle on a hard surface exaggerates many types of lameness, particularly those involving the lower limb structures and joints. The increased loading on the inside limb during a tight circle concentrates stress on that limb's structures. A horse that appears marginally lame or sound in a straight line may show much clearer lameness when trotted in a 6–8 metre circle.

Observe the horse circling in both directions. Lameness that is clearly worse when the affected limb is on the inside of the circle is typical of lower limb joint pathology. Lameness that is worse when the affected limb is on the outside of the circle is less common but can indicate upper limb or soft tissue issues. Note the directions and report this information to your vet.

Home Flexion Tests

A flexion test involves holding a limb in a bent position — typically 30–60 seconds — and then immediately trotting the horse away to see whether lameness increases in the first few strides. The rationale is that prolonged flexion increases intra-articular pressure and stretches periarticular structures: if a joint is inflamed, this provocation will transiently worsen discomfort.

As an owner, you can perform a basic fetlock flexion by picking up the lower limb, gently flexing the fetlock for 30 seconds, placing the foot down, and immediately trotting away with your helper. A significant increase in lameness over the first five to ten strides after release suggests the fetlock, pastern, or foot is involved. Do not over-interpret a mild response — many horses show a slight increase after prolonged flexion — but pronounced exacerbation is meaningful and should be reported.

Checking for Heat, Swelling, and Digital Pulse

After observing the horse in motion, systematically examine all four legs by hand. Run the back of your hand down the front and sides of each cannon bone and tendon area — the back of the hand is more sensitive to subtle heat than the palm. Compare each leg to the opposite one: a leg that is warmer than its pair is significant. Feel for any soft or firm swelling along the tendons, in the fetlock, or around the coronary band.

The digital pulse is felt by placing your fingers over the digital artery at the back of the fetlock. In a healthy horse this pulse is faint or imperceptible. A strong, bounding digital pulse — one you can feel easily without pressing — indicates active blood flow to the foot consistent with foot inflammation. This is one of the most important clinical signs to check for and is a key early indicator of laminitis. If you find a bounding digital pulse, box rest the horse immediately and call your vet. For more information on monitoring your horse's vital signs, see our guide to horse vital signs.

Looking at the Foot

Pick up each foot in turn and inspect the sole carefully. Look for bruising — areas of reddish or purple discolouration in the white sole, often near the toe or at the seat of corn. Look for any puncture wound — a small dark hole in the sole or frog that could indicate a nail or other foreign body penetration. Look at the shoe: risen clinches (the ends of the nails that have pulled up from the wall) or a shoe that has moved or twisted on the foot suggest the shoe has shifted and may be causing pressure.

Examine the frog for signs of thrush — dark, moist, malodorous tissue in the frog sulci indicating bacterial infection — and check the coronary band for any cuts, swelling, or heat.

When to Call the Vet

Always call your vet for: Grade 3 or above lameness (consistently visible at trot under all conditions); any lameness accompanied by significant heat or swelling in the limb; a bounding or easily palpable digital pulse; any foot wound, puncture, or foreign body; any horse that is very reluctant or completely refusing to bear weight; lameness following known trauma or a fall; and any lameness that has not improved after 24–48 hours of box rest. Early accurate diagnosis makes every subsequent treatment decision better — attempting to manage lameness without knowing the underlying cause is inefficient and risks worsening the injury.

Frequently Asked Questions

How do I tell which leg a horse is lame on?

For forelimb lameness, the head nods DOWN on the SOUND leg and rises on the lame leg. "Down on sound" is the key phrase to remember. For hindlimb lameness, watch the croup from behind: the hip on the lame side rises more — the hip hike.

What does the head nod mean in horse lameness?

The head nods down toward the sound leg as it bears the greater portion of body weight, and rises when the lame leg is loaded. The larger and more consistent the nod, the more severe the lameness.

What is a flexion test?

A flexion test involves holding a joint in a bent position for 30–60 seconds and immediately trotting the horse away to see whether lameness increases. Significant exacerbation in the first few strides suggests the flexed joint is involved in the cause of lameness.

When should I call the vet for horse lameness?

Call your vet for Grade 3 or above lameness, any lameness with heat or swelling, a bounding digital pulse, any foot wound, non-weight-bearing, or lameness not improving after 24–48 hours of box rest.

What is a bounding digital pulse in a horse?

A bounding digital pulse is a strong, easily palpable pulse in the digital artery at the back of the fetlock — a sign of active foot inflammation. In a normal horse the digital pulse is very faint. A bounding pulse requires immediate box rest and veterinary attention as it is associated with laminitis and acute foot conditions.

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Disclaimer: This article is for educational purposes only and does not constitute veterinary advice. Always consult a licensed equine veterinarian for diagnosis and treatment.