Horse lameness symptoms range from the most obvious to the most obscure. Lame horses may shift their weight restlessly from one foot to another. They may stand with their legs splayed out widely or tucked in under their bodies. Some hold a foot off the ground. When lame horses move, they accept more weight on the good leg than the bad leg, which causes their head to bob up and down. Watching the shouldersand hips, it's possible to see the good limb sink a little more than the sore limb because the good limb is accepting the weight of the body. Lame horses often don't turn circles smoothly and cannot run as far or as fast as sound horses.
Horses that are lame because of hoof problems withdraw their painful hoof when it is squeezed or tapped with a hoof tester. There may be pus draining from an abscess that occurs within the hoof. Hoof abscesses travel upward to drain above the hoof wall at the coronet band. The blood vessels traveling to the hoof may have a bounding pulse. Horses that are lame because of joint problems often have heat and swelling in the lame joint. Comparing the lame leg with a sound leg reveals the difference. Horses that become lame due to ligament and tendon problems often withdraw their leg if the ligament or tendon is pinched.
Lame horses often don't lift their hooves off the ground because lifting requires joints to bend, which causes pain. These horses take short steps and may drag the toe rather than swing it upward in a normal arc.
Since horse lameness has so many potential causes, and because it is influenced by conformation, nutrition, and activity, it can be hard to diagnose properly. Normally, veterinarians begin by asking these questions:
With this information, your veterinarian can perform a physical exam and look for heat, swelling, pain, and throbbing pulses. Your horse may be made to lunge at a walk, trot, and cantor. Your horse will be examined traveling in a straight line and in a circle. Your veterinarian will test for hoof pain and palpate the joints, spine, and muscles. If the problem is not obvious, your veterinarian may block the nerves.
Horse lameness exams can include different forms of diagnostic imaging: X-rays, ultrasounds, thermal imaging, MRI, and CT scans. The X-rays outline bones and identity bone chips, but are not useful for diagnosing soft tissue injuries. Ultrasound identifies soft tissue injuries but does not help diagnose bone problems. An MRI shows joint surfaces and soft tissues, such as tendons and ligaments. Thermal imaging identifies areas of inflammation. CT scans show all tissues, including bone.