What to expect when your vet assesses your lame horse

If your horse is displaying signs of lameness, you should call your local vet for a thorough assessment, as lameness can be caused by many different factors.

Your vet will want to observe your horse while it is moving as well as standing still and at rest. In addition, your vet will use his/her hands to feel ("palpate") the horse to detect any signs of heat, swelling and pain.

Your vet may grade the degree of lameness using a grading scheme. There are different types of grading scheme, such as the American Association of Equine Practitioners' Lameness Grading, shown below. Your vet may use this scheme or a different method of grading – either way, grading may be useful for the vet to check if your horse is responding to treatment by noting the improvement in lameness grade over time.

Assessing different movements

Walking: Your vet will probably watch your horse walk in a straight line as well as circled on both soft and hard surfaces. The walk is a useful gait to evaluate because a slower gait makes it easier to see slight changes from a "normal" walk. Different surfaces can be useful because some forms of lameness may be more accentuated on a hard surface than a soft one, and the reverse also is true. A hard surface also allows the vet to listen to the sound of the hooves contacting the ground. The lame leg usually contacts the ground with less force and this difference can sometimes be heard.

Trotting: Your vet may want to watch your horse trot in a straight line as well as in a circle, on both soft and hard surfaces. The trot is useful because it consists of a two-beat stride pattern, and the horse's weight is distributed evenly between diagonal pairs of legs.

Cantering: Sometimes the horse will be asked to canter or lope. This can be useful for detecting problems in certain areas such as the lower back.

Riding: In some cases, your vet may ask you to saddle and ride the horse, while he/she continues to evaluate the gait. Moving the horse up and down an incline can also be a useful aid to detect some types of lameness.

Other tests

Flexion tests: Your vet may flex a joint or joints and hold it in flexed position before asking the horse to move off again in walk and trot. This evaluates the range of motion and the response to flexion: after the area has been flexed does it increase the degree of lameness? Performing this type of test can help localise the site of lameness.

Hoof testers: These may be used to apply pressure on specific areas of the hoof to detect a response, which is usually related to pain in the area.

Nerve blocks: Your vet may need to inject local anaesthetic at various points along the leg or foot to temporarily numb a nerve. The horse is trotted again and the response to the block evaluated. Various nerves can be sequentially blocked and the observation process repeated. The vet will be watching for the horse to "go sound" when the nerve block has been successful and in this way, identify the site or region of lameness.

Further diagnostic tests: Your vet may want to use radiographs, ultrasound or more specialised to further assess your horse.