When a veterinarian evaluates a horse for lameness, its degree of lameness is graded on a scale from 0-5, often referenced in lameness exam. It is a universal lameness grading scale that veterinarians globally understand and ensures effective communication of the degree of lameness.
The Horse Lameness¬† Grading Scale
Grade 0: Lameness is not perceptible under any circumstances.
Grade 1: Lameness is difficult to observe and is not consistently apparent.
Grade 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.).
Grade 3: Lameness is consistently observable at a trot under all circumstances.
Grade 4: Lameness is obvious at a walk.
Grade 5: Lameness is so significant the patient appears unable to use the limb, “three-legged lame.”
At What Gait is Lameness Most Recognizable?
Trotting exposes lameness. Much of a lameness evaluation occurs with the horse at the trot because the trot creates the most concussion on their limbs and will often help make the lameness more obvious.
How Bute Can Affect The Lameness Grade
A horse’s pain threshold can be altered by giving a pain reliever a day before a lameness exam. Horses have a pain threshold, and if someone provides them Bute the day before we arrive to do a lameness exam, they will often be sound. They’re not sound, but the pain is now below their threshold, and they don’t show the signs of pain, making it challenging to provide an accurate evaluation.
Take Away Message
The next time you’re trying to explain a lameness to your veterinarian, see if you can recognize where it falls in the grading system. It may be beneficial in communicating the lameness.