© TANUVAS, 2011 EXAMINATION OF EQUINE FOR LAMENESS

© TANUVAS, 2011 LAMENESS » An abnormality of gait that is caused by pain and / or restriction of movement. » Such 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.

© TANUVAS, 2011 THE MOST COMMON CAUSES OF LAMENESS The basic processes that cause disease can be remembered by using the acronym DAMNIT D: degenerative, developmental A: allergic, autoimmune M: metabolic, mechanical N: neoplastic (tumors), nutritional I: infectious, inflammatory, immune-mediated, ischemic (low blood flow), iatrogenic (man-made), idiopathic (unknown) T: traumatic, toxic

© TANUVAS, 2011 VETERINARY EXAMINATION Veterinary Surgeons use the following procedures to evaluate lameness and determine the cause: history physical examination (observation, palpation, manipulation) gait evaluation joint flexion tests diagnostic anesthesia - regional nerve blocks and joint blocks

© TANUVAS, 2011 CONTD… radiography (x-rays) ultrasonography thermography diagnostic imaging - the method chosen depends on the veterinarian's suspicions - radiography (x-rays) - bones and joints - ultrasonography - soft-tissue problems, such as tendon and ligament injuries, and joint surfaces - thermography - body surface temperature imaging, looking for areas of inflammation (increased temp.) or reduced blood flow (decreased temp.)

© TANUVAS, 2011 CONTD… nuclear scintigraphy (bone scan) computerized tomography (CT) - nuclear scintigraphy (bone scan) - soft-tissue phase for soft-tissue inflammation; bone phase for bone or joint problems - computerized tomography (CT) - any tissue, but mostly used for bone problems - magnetic resonance imaging (MRI) - mostly soft tissues and joint surfaces therapeutic trial - presumptive diagnosis based on response to treatment

© TANUVAS, 2011 PHYSICAL EXAMINATION As part of every equine lameness examination, a thorough general physical examination should be carried out. It is important to begin the physical examination by standing back and observing the entire horse from the front, side and back. Next, an in-depth palpation is carried out for each leg, first in the weight-bearing position, and then with the leg flexed and in the non-weight-bearing position. Each of the joints and soft tissue structures is palpated for heat, effusion, pain, or signs of resistance to manipulation.

© TANUVAS, 2011

© TANUVAS, 2011

GAIT EVALUATION A firm, nonslippery surface (eg, hardcore fine gravel) is ideal for trotting on a straight line and for lunging on a firm surface. It also provides an opportunity to listen to the footfall and consider this information along with the visual appraisal. However, feet of different shapes make slightly different impact sounds, which may be confusing.

© TANUVAS, 2011 CONTD… Although a horse may be regular in its stride, it may have a slightly weaker limb, particularly if recovering from a previous problem. Lunging on tarmac (asphalt) or concrete increases the risk of the horse slipping. It also generally alters the gait so much that it has little value in lameness examination. Leading the horse on a circle at a trot also tends to alter the horse’s stride too much; the horse cannot move its neck and instead “sets” its head on the leader’s hand.

© TANUVAS, 2011 CONTD… Assessing the horse at a canter, which requires a softer surface, is always important. A surprising number of horses with lower back pain may appear normal at a trot but are unable to maintain a normal 3-beat canter rhythm or may canter disunited.

© TANUVAS, 2011

© TANUVAS, 2011 FLEXION TESTS Flexion tests are useful diagnostic tools. The range of movement and response to passive flexion, along with any suggestion of increased lameness or onset of lameness following flexion, should be observed. The distal phalanges in both forelimbs and hind limbs should be flexed independently of carpus and hock to obtain maximal information.

© TANUVAS, 2011 CONTD… However, results of recent studies have suggested that “false-positive” results may be seen if excessive forces are applied. Consistency should always be applied, and individual experience used. A single positive flexion test without associated lameness may not be of significance and in some horses has proved to be a lifelong observation.

© TANUVAS, 2011 DIAGNOSTIC NERVE AND JOINT BLOCKS These analgesic techniques are perhaps the most important tools used to identify the location of lameness. Working from the foot up, the veterinarian temporarily deadens sensation to specific segments of the limb, one joint 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.

© TANUVAS, 2011 DIAGNOSTIC IMAGING Radiographs. X-rays are useful in identifying damage or changes to bony tissues. Radiographs 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

© TANUVAS, 2011 RADIOGRAPHY

© TANUVAS, 2011 CONTD… Ultrasound (Sonograhy. This procedure uses ultrasonic waves to image soft-tissue problems, such as tendon and ligament injuries, and joint surfaces Scintigraph(Nuclear scanning). Radioisotopes injected intravenously into the horse are concentrated in inflamed areas. These areas can be scanned with a gamma camera, providing an image of the trouble site. nuclear scintigraphy (bone scan) - soft-tissue phase for soft-tissue inflammation; bone phase for bone or joint problems

© TANUVAS, 2011 CONTD… Arthroscopy. –This procedure allows optical examination of internal joint tissues or tendon sheaths. It requires general anesthesia but may be the only way to define the damage. –Some diagnoses can only be made with arthroscopy

© TANUVAS, 2011 CONTD… computerized tomography (CT) - any tissue, but mostly used for bone problems magnetic resonance imaging (MRI) - mostly soft tissues and joint surfaces Blood, synovial (joint) fluid, and tissue samples. -These samples can be examined for infection or inflammation. Such examinations usually require laboratory testing. thermograph - body surface temperature imaging, looking for areas of inflammation (increased temp.) or reduced blood flow (decreased temp.)