Your horse has just come up lame. While you go through this assesment / treatment / referral paradigm best would be to allow the horse to rest standing still, particularly if he is non-weight bearing on a leg. If he can walk without too much difficulty, he can be put in a stall.

Lameness is defined as a change in gait or way of going in a horse and is a common event. It is not a disease but a symptom of one (or rarely a combination) of the following diseases:

• Pain in the feet, legs, back, or neck
• Mechanical problems of the muscoskeletal system
• Muscular Weakness
• Peripheral nerve disease
• Central nervous disease

Of course proper treatment will depend on an accurate diagnosis however horses often come up lame for reasons that are not immediately obvious. This article and it's links takes you through a step by step paradigm to help you decide do you have an emergency, when you need a vet, and considerations for diagnosis and proper first aid for an unknown lameness in your horse.

When your horse first comes up lame, quickly assess the general stature of the horse: is the horse acting normal, has an appetite, and are his vital signs, including temperature, normal? If there are general signs of illness you should address these issues first, ...more.

To assess the seriousness of a problem you first have to determine where the pain is coming from and the first step in localization is determining which leg hurts. When very lame picking out the lame leg is not difficult as the horse will not bear full weight on when standing and at a walk the limp with decrease weight bearing on the lame leg obvious. When the lameness is only obvious at the trot, can you pick out which leg or even whether it is a front or rear lameness? Frequently even experienced horsemen make mistakes on which leg. If you are having trouble localizing the lameness to a particular leg or structure in the leg study, Localizing Lameness in the Horse.

Once the leg has been identified, the next step is a thorough exam of the foot and leg. Not only is this a visual exam but involves palpation and flexion of the joints.

• No matter what is going on it always behooves you to pick the feet up, clean them out, and give them a careful inspection and check for heat. After brushing or washing all the dirt off the legs should get a good inspection, and careful palpation. You are looking for injuries, punctures, foreign bodies, swelling, heat, and pain on palpation. If the foot is hot with bounding pulse consider a foot abscess or nail puncture in the sole. If you localize the problem to the foot, see the article First Aid for Foot Problems.
• If you still cannot localize the lameness see Acute Lameness of Unknown Caus below.