Lameness Identification in the horse

Lameness Introduction

Lameness is one of the most highly reported disease in horses, accounting for 29% of all diseases in 2018

Even for the most experienced horse owners/ vets out there it can be difficult to identify

Common causes of lameness

Lameness can be caused by conditions in the foot, distal limb, proximal lim, spine and neck

The most common cause of lameness in the horse is a foot access (infection inside the hoof)

Other causes of lameness include:

• Sole bruising, corn, penetrating wound into the hoof, white line disease, navicular degeneration, laminitis, soft tissue injuries (such as tendon damage), arthritis, fractures

Forelimb lameness

The most common clinical sign of forelimb lameness at a trot is the head nod

• The horses head will move up when the lame foot is weight bearing, and drop down when the sound foot is weight bearing

Other clinical signs of forelimb lameness at a trot include:

• shortened stride (the horse will reach their lame foot forwards less and have a shortened stride on the lame side, this is easiest to asses by looking at the horse from the side as they trot past you or lungeing)

• irregular strides (listen to teh sounds of the foot beats- are they regular)

• foot not landing flat (this is easiest to assess in walk)

Hindlimb lameness

The most common clinical sign of hindlimb lameness at a trot is hip hike/ asymmetry

• the tuber coax of the lame leg will move more than the tuber coax of the sound leg. This is easiest to assess with the horse moving away from you

Toe dragging and leg not swinging straight (drag the lame foot on the ground, swing leg as they move)

Shortened stride (the horse will reach their lame foot forwards less and have a shortened stride on the lame side, this is easiest to asses by looking at the horse from the side as they trot past you)

Irregular strides (listen to the sounds of the hoofbeats- are they regular)

Foot not landing flat (this is easiest to assess in walk)

In severe hindlimb lameness, you will see a head nod on the opposite forelimb

Hindlimb lameness in canter

In canter, a horse will push off using its inside hindlimb

This means that if a horse is right hindlimb lame, it will be reluctant to canter on the left rein (circling left)

This is because the right hind is on the inside of the circle and will be taking most of the horses weight/ pushing off- not ideal if it is sore

Bilateral lameness

‘bilateral’ means affecting both sides.

A bilateral lameness would be a horse who is lame on both forelimbs or both hindlimb.

Bilateral lameness can be very tricky to identify.

Lameness occurs because the horse does not want to bear weight on the lame foot so alters its stride

If the horse does not want to bear weight on either leg, the gait may appear symmetrical/ normal

Clinical signs of bilateral lameness

Shortened stride on both lame limbs

Behaviour and performance changes

Lameness may shift between legs- ensure you watch horse for long enough

Lameness behaviour

Lameness is not always easy to spot. Some horses may be more ‘robust’ and some lameness may be very mild

Often horses show subtle pain through behavioural signs and performance changes

Examples include:

Reluctance to pick up feet, refusing at jumps, tail swishing, ears back, mouth opening, aggression when touching back/ putting tack on

The importance of good history

To be able to understand the causes of lameness, we need to take a good history, investigating:

• the duration of the lameness- is the issue an acute/ traumatic cause, or a more insidious onset such as arthritis

• the severity of the lameness

• the horses workload- understand the daily stresses and stains this horses body is going through. Important for diagnoses and adjusting management going forwards into treatment

• history of previous lameness- is this a recurring problem

Palpitation

Feel the horse’s muscles, bones and joints- working from head to tail

Repeat the exam for both sides of the horse- assessing symmetry

What key factors are you looking for when palpitating?

Heat

Pain

Swelling

Wounds

Muscle wastage

Asymmetry

Digital pulses

The foot

Many causes of lameness in the horse come from the foot, therefore it is very important to pick up their feet and have a look

Digital pulses

Gently place your thumb on one side of the fetlock, and your first 2 fingers on the other side, feeling for any heat or bounding pulses

Bounding pulses indicate inflammation/ pain in the foot

Look for any areas of bruising, discharge, or things in the foot which aren’t supposed to be there

Hoof testers

• squeeze around the hoot and localise pain in the sole

Dynamic lameness exam- walk

Walk the horse directly away from you, and directly towards you

• allows the horse to get used to the area

• look for any obvious lameness

• assess how the horse turns around at each end- this can exacerbate lameness

• watch the horses feet- are they landing flat, are the toes dragging on the floor, are all of the legs moving the same or is one leg moving differently?

Dynamic lameness exam- trot

Trot the horse directly away from you, and directly towards you

Pay attention to the hip hike as the horse trots away from you, and head nod as the horse trots towards you

Dynamic lameness exam

Lungeing and flexion tests may also be carried out during the lameness assessment

Lungeing: lameness is often more pronounced when the horse is worked in a circle so lungeing can help vets to identify more subtle problems

Flexion tests: following the initial trot up assessment, flexion tests may be performed one at a time and the horses response will be assessed by comparing the movement to the original trot up. Flexion tests involve holding the leg fixed in a flexed position for a period of time and then trotting the horse away. By placing more pressure on the joints any issues that may be caused by lameness should become fore obvious

Dynamic lameness exam

Use of different surfaces

Repeating the dynamic assessments (walk, trot and lunge) on hard flat ground e.g. concrete, and then on a soft arena surface e.g. sand/ rubber menage

Some lamenesses may be more pronounced on certain surfaces

• e.g. sole bruising in the foot will be more pronounced on a hard, concussive surface

• tendon damage can sometimes be more pronounced on a deep soft surface when the tendons become under more strain