Preventing 'Tying Up'

Did you know that performance horses are always at risk of Tying Up? Tying Up is a broad term that describes a wide variety of muscle disorders that affect the performance horse. Ipos Technology’s Training App can help in preventing it. The App helps you to see where you need to include enough time for a warming-up and cooling down, which can prevent the horse getting Tied Up. Furthermore, the App shows you how intense the training was for your horse, so that you can adapt concentrated feed to your daily training, so that the horse only gets the feed that it really needs. Tying Up can be prevented many cases with reduced work and feeding less concentrates.

Horse with light 'Tying Up'

The Ipos Technology Training App monitors daily training and calculates how intensive it was for your horse. It will advise a less intense training for the following day, if the day’s training was high intensity. However, this does not mean that your horse should stand in the stable. It means that your horse should be active in movement, but with a lower intensity to prevent e.g. Tying Up. In this blog, we explore what Tying Up is, what causes it, what the symptoms are, how long your horse will need for recovery, how you can prevent it, and present a check list on what to do if the horse is Tied Up.


Tying Up has been observed in many different horse breeds. Most frequently, it is seen in race horses (which have a 6% higher risk than other horses) and polo ponies (which have a 13% higher risk than other horses). Worldwide, between 5% and 7% of Thoroughbreds are affected by Tying Up every year. With two- and three-year-old horses in training most often affected. In addition, mares and nervous horses are more severely affected than stallions and horses that are more relaxed. In general, horses with Tying-Up lose six days of training per episode.

What is Tying Up?

Tying-up is a broad term that frequently is used to describe a wide variety of muscle disorders that affect the performance horse. Other names given to this syndrome include exertional rhabdomyolysis syndrome (ERS), exertional rhabdomyolysis (ER), Monday morning disease, azoturia and set fast.

In the past, horses had to work hard on the field during the week and were rested at the weekend. They still, however, were given the same ration of feed at the weekend. Now, horses frequently develop metabolism problems, because they often have a different balance between movement and feed.

The energy that a horse receives is used by its muscles. A horse that moves a lot will need more energy than a horse that doesn´t move much (e.g. one that stands in the stable a lot). The energy that a horse consumes must be in proportion to the energy that the horse receives. When a horse consumes energy, and retains a surplus that is not used and burned how it normally should, or sufficient oxygen cannot be supplied to properly burn all (surplus) energy, the homeostasis of the Calcium inside the cells is interrupted. This Calcium is needed for muscle contraction. If it cannot be filtered back, the muscle cannot relax. The consequence is mechanical stress and damage to the muscle fibers. Moreover, other substances are released. And all this leads to ´Tying Up´.

What causes Tying Up?

There are several causes for Tying Up, but the outcome is the same – cramp in the horse’s muscles. The possible causes are listed below:

1. Loss of electrolytes through massive sweating

- This can occur, because the horse is under too much strain (which could be congenital).

- Training was too hard, especially if the horse has a bad condition or is unwell.

2. The horse became chilled during or after training, due to weather conditions (in which the horse cools down too fast after training and muscle cramp occurs).

3. The horse has a metabolic disease.

4. The horse has a deficiency of Vitamin E or Selenium.

5. The most common cause is that the horse is overfed concentrate feed or grain.

- The horse consumes too much carbohydrate, relative to the movement that it makes.

6. Congenital factors:

- PSSM1 (Polysaccharide Storage Myopathy) mostly detected in Quarter Horses, Paints, Appaloosas, Gypsy Cobs, Haflingers and draft horse breeds.

o Horses with PSSM1 have problems with the storage of sugar in the body.

o In this condition, sugar is absorbed from the blood much faster than normal and is transported into the muscle.

o A lot of glycogen is also built up in the muscles, which disrupts energy management during exercise, and makes them Tie-Up more quickly than other breeds of horses.

- PSSM2 (Polysaccharide Storage Myopathy) is a dominant, progressive muscle breakdown disease caused by an error in build-up of the amino acid chain in the muscle cells.

o Chronic protein uptake/production issue resulting in muscle breakdown.

o Horses with PSSM2 are extremely sensitive to negative nitrogen balance which can be caused by inflammation, severe stress, vaccinations, injuries, viruses and sometimes even by chemical deworming.

What are the symptoms?

The symptoms of Tying Up can be categorized as light, moderate and heavy. There is also a difference between acute and chronic Tying Up.

The symptoms of light Tying Up are: back flexion, slower movement, and a stiffness in the hindlegs. Horses with a moderate Tying Up find it harder to walk, movements are stiffer and more contracted, and muscle cramping is seen. Muscle cramp in horses feels the same to the horse, as it does to humans. Horses suffering from the last category of Tying Up (heavy) are not able to move, sweat heavily, have an elevated temperature of up to 40ºC – 40.5ºC, have dramatically increased heart and respiratory rates, and it is also possible that their urine has a dark red color. This occurs if the cramping is severe enough for myoglobin to be released from the damaged muscle, and then from blood to kidney and into the urine. This can cause severe problems with the kidneys. The muscle groups along the back and rump of the horse can contract massively. The muscles contract and do not relax. The horse will experience pain, and if you press our hands along the muscles on either side of the spine, the muscles feel hard as a rock. In some cases, Tying Up can lead to death if kidney failure occurs.

Difference between muscle soreness and cramping

Not every horse that has muscle pain or muscle cramp after exercising becomes ´Tied-Up´. In general, there is a difference in muscle soreness and cramping. Also is there difference in acute Tying Up and chronic Tying Up.

1. Muscular soreness is an anticipated result of exercising and is healthy. It typically peaks 24-72 hours after activity. It is the result of safe, small-scale damage to muscle fibers, and results in the muscles feel tight with a slight ache. Movement may feel a little uncomfortable, but moving and gently stretching the muscles also help to decrease soreness.

2. Muscular cramping is a sudden and involuntary contraction of one or muscles and is painful. Cramps happens after long periods of exercises or physical labor and dehydration. A good stretch before and after exercise prevent cramps occurring.

- Acute Tying Up: This classification applies to horses that experience an episode of generalized Tying-Up on rare occasions. This will generally involve muscle stiffness and cramps.

- Chronic Tying Up: This is when a horse experiences repeated episodes of Tying Up, with the first episode usually occurring at a young age. This can be quite a problem, and with repeated bouts of Tying Up may cause irreversible muscle damage.

How long will it take for a recovery?

If a horse has suffered a light or moderate episode of Tying Up, it is important to keep it warm and feed only roughage, minimize any stress and draughts, and not feed any concentrates until all metabolic waste products are released from the body. The horse should be kept in a box for one week. If the horse walks in the stable, it can be walked several times a day in-hand, for at least 10-15 minutes each time. To be sure that recovery is progressing, it is better to arrange for some blood samples to be taken to measure the amount of muscle enzymes that may be still in the blood. If this looks good, the horse may trot a little again. Recovery training is about building up slowly, because a relapse is possible, of course. In particular, concentrated feed must be adapted to the work that the horse does.

How can Tying Up be prevented?

Most importantly, your horse should be active with movement after days of heavy work, and does not stand still in the stable. The best thing is to turnout the horse into the field, or non-grassed enclosure, where it can move freely, or use a walker. The muscles need rest to recover, but this does not mean that your horse has to stand in the stable. A bit of movement aids recovery. And the concentrated feed should be regulated for that day, so that there no surplus of nutrients is fed. In this way, the metabolic waste products can be removed much better from the horse’s muscles ,and the chance of another Tying Up episode is, thus, greatly reduced. Furthermore, there should always be enough time made to include really good warming-up and cooling down sections within each training session.

Walk in-hand

Put your horse into the field

Turnout in a non-grassed enclosure can also provide a good solution, if a field is not available.

Basic check-list for Tying Up:

· Stop exercising the horse and move it to a box stall. Do not force the horse to walk.

· Call your veterinarian.

· Rug the horse, if the weather is cool.

· Determine if the horse is dehydrated due to excessive sweating. When skin is pinched, it should spring back, and the horse’s saliva should be wet, not tacky.

· Provide fluids – Small frequent sips of water. Electrolytes (potassium, sodium, and chloride) may be added to drinking water, if palatable to the horse. Plain water should always be available as an alternative. If the horse is dehydrated, your veterinarian might give intravenous fluids. Once cool, the horse can have free access to water.

· Relieve anxiety and pain. Drugs may be prescribed by your veterinarian.

· Remove grain and feed; provide only hay until signs subside.

· Walking in-hand or small enclosure turnout is good, once the horse walks freely, usually within 12-24 hours.

· When blood creatine kinase (a blood enzyme) is normal, slowly recondition the horse back to the previous work level.

· If the problem reoccurs, have the horse evaluated for a specific cause of recurrent Tying Up.

· Consider changing the diet, feed less grain and more fat, and make sure the mineral intake is balanced. Elevated levels of Vitamin E, Selenium and Magnesium may also be useful (consult nutritionists).


· Barrey, et al., 2012. “Transcriptome analysis of muscle in horses suffering from recurrent exertional rhabdomyolysis revealed energetic pathway alterations and disruption in the cytosolic calcium regulation.” Animal Genetics 43, 271–281.

· Harris, P. (1991). “The equine rhabdomyolysis syndrome in the United Kingdom: Epidemiological and clinical descriptive information.” British Veterinary Journal, 147(4), 373–384.


· Harris, P., & Snow, D. H. (1986). “Tying up the loose ends of equine rhabdomyolysis.” Equine Veterinary Journal, 18(5), 346–348.

· Hygain. 2019. “What is Tying up in horses?”


· Isgren et al. 2017. “Epidemiology of Exertional Rhabdomyolysis Susceptibility in Standardbred Horses Reveals Associated Risk Factors and Underlying Enhanced Performance.”

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· Van Valberg, S. J. (2012). “Exertional Rhabdomyolysis: Diagnosis and Treatment.”