Muscle stiffness, also known as tying-up and Monday morning disease, is a condition where there is a disturbance in muscle metabolism. Due to the excessive production of lactic acid in the muscle cells, the muscle cells can expand and compress blood vessels and muscles. If muscle cells are compressed for too long, they can die, after which waste products enter the bloodstream. This can lead to acidification primarily in the muscles of the hindquarters, loins, croup, and back muscles.

Causes of muscle stiffness

The most common cause of muscle stiffness in horses is that a horse receives too much concentrated feed in proportion to the amount of effort the horse needs to exert. This leads to an abnormal metabolism in the muscles. Overtraining when sick or in poor condition, overworking young horses, a disturbed electrolyte balance, dehydration, and a deficiency of vitamin E or selenium can also be causes of muscle stiffness.

Symptoms of a horse with muscle stiffness

In muscle stiffness, a distinction is made between mild, moderate, and severe muscle stiffness. With mild muscle stiffness, horses often stand with an arched back and walk stiffly in the hindquarters. Moderate muscle stiffness can cause horses to have a shortened stride, with muscles being stiff, swollen, and painful, and the hindquarters trembling. With severe muscle stiffness, horses often do not want to walk and sweat profusely. Anxiety, dilated nostrils, wanting to lie down, not wanting to get up, and an increased respiratory and heart rate also occur. Additionally, reddish-brown urine can result from the breakdown products of the muscles ending up in the urine.

Treatment of a horse with muscle stiffness

If symptoms of muscle stiffness occur, it is advisable to contact the vet immediately. The vet will take blood to determine if the horse has muscle stiffness and how severe it is. After the examination, a vet usually administers pain relief and anti-inflammatory drugs. Furthermore, treatment consists of rest. For example, do not force a horse with muscle stiffness to move and transport it as little as possible. You can also keep the horse warm under a blanket. In addition, dietary adjustments may be necessary. For example, work with your vet to create a diet plan. Recovery from muscle stiffness can take weeks to months. Sometimes a horse does not fully recover.

Prevention

To prevent muscle stiffness in horses, it is important to properly match your horse's nutritional needs to the expected effort. For example, less concentrated feed can be given during a period of rest. It is also important not to leave your horse in the stable all day and that the horse has access to sufficient roughage. Make sure that the energy value of the hay is not too high. Finally, a training schedule can be drawn up. A good warm-up and cool-down, for example, contribute to the removal of already produced lactic acid.