Lameness Examination

EXAMINATION PROCEDURES (from AAEP) 

Veterinarians have specific systems for performing examinations, depending on the reasons for the evaluation. However, essential features of a thorough examination include: 

The medical history of the horse.

The veterinarian asks the owner questions relating to past and present difficulties of the horse. He or she also enquires about exercise or work requirements and any other pertinent information. 

A visual appraisal of the horse at rest.

The veterinarian will study conformation, balance and weight-bearing, as well as look for any evidence of injury or stress. 

A thorough hands-on exam.

The veterinarian palpates the horse, checking muscles, joints, bones and tendons for evidence of pain, heat, swelling or any other physical abnormalities. 

Application of hoof testers to the feet.

This instrument allows the veterinarian to apply pressure to the soles of the feet to check for undue sensitivity or pain. Many practitioners will concentrate on the front feet, as 70 to 80 percent of the horses weight will be supported by the front limbs. 

Evaluation of the horse in motion.

The veterinarian watches the horse walking and trotting. Gait evaluation on a flat, hard (concrete) surface usually yields the most. Observing the horse from the front, back and both side views, the veterinarian notes any deviations in gait (such as winging or paddling), failure to land squarely on all four feet and the unnatural shifting of weight from one limb to another. The horse also walks and trots in circles, on a lunge line, in a round pen and under saddle. The veterinarian looks for signs, such as shortening of the stride, irregular foot placement, head bobbing, stiffness, weight shifting, etc. 

Joint flexion tests.

The veterinarian holds the horse's limbs in a flexed position and then releases the leg. As the horse trots away, the veterinarian watches for signs of pain, weight shifting or irregular movement. Flexing the joints in this manner may reveal problems not otherwise readily apparent 

DIAGNOSTIC TESTS (from AAEP)

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. 

Diagnostic nerve and joint blocks. 

These analgesic techniques are perhaps the most important tools used to identify the location of lameness. Working systematically, the veterinarian temporarily deadens sensation to specific segments of the limb, one region at a time, until the lameness disappears. This procedure isolates the area of pain causing the lameness. Blocks can also help determine whether the condition is treatable.

Radiographs are useful in identifying damage or changes to bony tissues. 

They should be interpreted only by an experienced and knowledgeable veterinarian, since not all changes are cause for concern. Radiographs provide limited information about soft tissue, such as tendons, ligaments or structures inside the joints, which are often the source of lameness. 

Ultrasound (sonography). 

This procedure uses ultrasonic waves to image internal structures. 

Blood, synovial (joint) fluid and tissue samples. These samples can be examined for infection or inflammation . Such examinations usually require laboratory testing.