Learning what constitutes normal muscle tone can prevent injuries, even tying-up. Although terms like “tight” and “hard” are used to describe fit horses, their muscles should feel anything but.
A normal, well-conditioned muscle at rest is pliable. It has a texture and degree of yield to finger pressure like an uncooked pot roast. Unconditioned muscle feels like hamburger. The conditioned muscle should roll away from your fingertips if you press against its edge, and you should be able to insert your fingertips easily into the clefts between muscle bellies and at edges of the muscle (such as at the front edge of the shoulder).
The gluteals (rump) are covered by thick skin and have an overlying layer of fat that makes it difficult to feel the condition of the muscle underneath. The triceps (above the elbow) and quadriceps (attaching to the stifle) should relax with the horse standing, as will the pectorals (chest). Muscles along the shoulder and in the hamstring area will be under a little more natural tension/stretch with the horse standing but should still be easy to indent.
Muscles that feel hard or cord-like are abnormal/overworked, resulting in spasm. Muscle that tightens when you gently prod it is abnormal. Desensitize the horse by stroking the area you want to examine with a firm pressure for a few minutes before directly putting pressure down into a muscle belly or between muscles. If you still get tensing and the horse tries to avoid the pressure, muscle pain is present.
Check your horse’s muscles after a heavy work and any time he seems to be off yet you can’t pinpoint foot/joint problems. Pay close attention to the pectorals, hamstrings and top of the neck/poll.
If pain/spasm is detected, the horse should be rested with lots of turnout that lets him work through the spasm by stretching and rolling. Gentle massage (five to 10 minutes per location) with witch hazel, baby oil or diluted liniments (dilute to 25% strength with witch hazel) will also help relieve spasm and encourage blood flow. Walking also is beneficial.
We wouldn’t bother with anti-inflammatories. Most have little effect on muscle pain. If the pain is really severe, your vet may recommend Methocarbamol (Robaxin).
If the horse has repeated problems with muscle pain despite a sane conditioning schedule, be sure his diet has generous amounts of electrolytes (see August 1999), vitamin E and essential trace minerals.
When resting muscle tone is abnormal bodywide, blood tests for muscle enzyme levels are in order as the horse may be on the verge of tying-up. Increase the amount of long, slow work with proper cooling out and lots of turnout. Maximize nutrition, maybe adding a vitamin B supplement (see July 1998) as suboptimal B levels interfere with efficient energy generation. If the horse ties up anyway or his muscle tone doesn’t improve, get a tying-up evaluation (see April/May 1998).