Stress, strain or injury can take a toll on any horse, even one with no obvious conformation defects. When lameness occurs, you should contact your veterinarian promptly. A prompt examination can save you time, money and frustration by diagnosing and treating the problem immediately, possibly preventing further damage. The goal of such early examinations is to keep small problems from becoming big ones.
Lameness evaluations are also routine in most purchase examinations. When your veterinarian evaluates an animal you are considering for purchase, you may be forewarned about potential problems and should be able to make a more informed decision.
Traditionally, lameness has been defined as any alteration of the horse's gait. In addition, lameness can be manifest in such ways as a change in attitude or performance. These abnormalities can be caused by pain in the neck, withers, shoulders, back, loin, hips, legs or feet. Identifying the source of the problem is essential to proper treatment.
Veterinarians have specific systems for performing examinations, depending on the reasons for the evaluation. However, essential features of a thorough examination include:
Diagnostic procedures are often necessary to isolate the specific location and cause of lameness. Lameness is best treated with a specific diagnosis. If your veterinarian has cause for concern based on initial examination, he or she may recommend further tests, including diagnostic nerve or joint blocks, radiographs, nuclear scanning, ultrasound, arthroscopy or examination of blood, synovial fluid and tissue samples.
AAEP LAMENESS SCALE
Because each horse has unique performance characteristics, evaluating lameness can be challenging. Experienced riders may detect minor alterations in gait before they are apparent to an observer. Lameness may appear as a subtle shortening of the stride, or the condition may be so severe that the horse will not bear weight on the affected limb.
With such extremes of lameness possible, a lameness grading system has been developed by the AAEP to aid both communication and record-keeping. The scale ranges from zero to five, with zero being no perceptible lameness, and five being most extreme. The AAEP guidelines explain the grading system this way:
0: Lameness not perceptible under any circumstances.
1: Lameness is difficult to observe and is not consistently apparent, regardless of circumstances (e.g. under saddle, circling, inclines, hard surface, etc.).
2: Lameness is difficult to observe at a walk or when trotting in a straight line but consistently apparent under certain circumstances (e.g. weight-carrying, circling, inclines, hard surface, etc.).
3: Lameness is consistently observable at a trot under all circumstances.
4: Lameness is obvious at a walk.
5: Lameness produces minimal weight bearing in motion and/or at rest or a complete inability to move.
MORE ABOUT OBSERVING THE HORSE IN MOTION
The veterinarian should observe the horse on both soft and hard surfaces, since different types of lameness may become apparent with different footing. In addition, lameness may only be apparent when the horse is under saddle, or it may be manifest only at liberty or on a longe line when the horse can be evaluated without the influence of the rider.
A horse's walk and trot may be especially revealing. The slower gait of the walk makes it easier to observe slight deviations that aren't readily apparent at a faster pace. However, the trot is perhaps most useful for evaluating lameness because it is the simplest gait, consisting of a two-beat stride pattern, and because the horse's weight is distributed evenly between diagonal pairs of legs. In some cases the speed and concussion of a faster pace (i.e. canter, gallop) is needed to help demonstrate the lameness.
LAMENESS EVALUATIONS IN RELATION TO PURCHASE EXAMS
Evaluation for the presence of lameness should be part of every purchase evaluation. While it is impossible to predict a horse's actual performance, the veterinarian can provide information regarding lameness or potential lameness by evaluating conformation, movement, medical history, past performance and existing medical conditions. The extent of the exam will be determined by the buyer and veterinarian. Value, intended use and long-term goals may be factors in selecting certain exam procedures. For example, radiographs, sonograms and other diagnostic tests provide comprehensive pictures of the horse's condition, but they also add to the exam's cost. Remember, your veterinarian cannot tell you whether to buy a horse or not, they can simply assist you in finding current or potential problems.
The most important question your veterinarian will ask is: What will you be doing with this horse? Your veterinarian will then weigh conformation, movement and medical considerations against the type and level of performance expected. A horse that is fine for a daily pleasure ride may not hold up under more strenuous activities.
In the purchase lameness exam, the veterinarian will try to determine two things:
1) Is the horse lame at the present time, or are there existing conditions that deserve a closer look?
2) What is the likelihood that the horse will remain serviceable for its intended use? Age, health, expected level of activity, conformation and past use will be considered. The veterinarian will inform the owner of the relevant facts and risks, and the owner can then decide whether to purchase the horse.
LIMITATIONS OF PURCHASE EXAMS
It is important to remember that even a favorable report following a lameness exam does not guarantee there are no problems. Many factors can affect a horse's short- and long-term ability to perform. Factors in the lameness equation include many variables, such as:
In order for your veterinarian to evaluate a horse fairly, the animal should be fit, conditioned and in training for its intended use. A horse that has been laid off for an extended time will be difficult to evaluate for lameness. One option may be to ask that the horse be returned to training and then re-examined after 30 to 60 days. Depending on the horse's value, such a request may be reasonable. Ask your veterinarian.
Lameness is a complicated condition, with many possible causes. Be a conscientious observer. If you suspect a problem, discontinue riding your horse and seek advice from your veterinarian promptly. By identifying even a minor lameness and acting swiftly to correct it, you will minimize the risk of injury to the horse and yourself, and you will be rewarded by better performance and a longer useful life from your horse.
For more information, contact your veterinarian.