Tying-up in Horses

Tying-up and muscle cramps during or after exercise are a relatively common problem in performance horses. Normally, horses tie-up along the back and hind leg muscles, although in some severe cases, horses will cramp in all muscles, including the shoulder. Although the signs of swelling, stiffness and soreness in the affected muscles are well known, the exact underlying causes of tying-up are not fully understood. However, management practices and nutritional deficiencies are strongly suspected of causing the disorder.

Causes of tying-up

• Horses that are dehydrated, suffering sodium, potassium, magnesium or selenium loss from heavy sweat output, or those grazing pastures low in selenium, are reported to be more likely to tie-up during exercise.
• It is also not uncommon for horses to tie-up after a couple of days of rest on a full grain ration, or to tie-up in early training when pushed too hard, too quickly.
• Tying-up is most common in poorly conditioned horses that are given high energy rations in excess of their exercise needs, particularly those given irregular exercise due to minor lameness, bouts of wet weather, or when travelling.
• Young, nervy or flighty fillies on grain diets, particularly oats, seem especially prone to tying-up. Many of these nervy horses "compete before their race", and are likely to tie-up during training and competition particularly if they have been transported over long distances.

First-aid for tying-up

Tying-up can occur during work, or within the rest period immediately following exercise. If a horse ties-up during work, stop further exercise, unsaddle and cool the horse down slowly by walking it for 2-3 minutes to lose heat and work the muscles gently without a load. The muscle groups affected, usually the croup or rump muscles, can be massaged for 1-2 minutes or so, interspaced with walking the horse for 2-3 minutes. Repeat this process until the stiffness or cramps are relieved.

What to do with severe cases of tying-up

If a horse ties-up severely, your vet should be consulted immediately. Where a horse ties-up severely and is obviously very uncomfortable and in a state of shock, it is important not to force the horse to walk or move, as severe and permanent muscle damage may result. If this occurs during training or competition, keep the horse warm and seek veterinary advice as soon as possible. If a horse cannot be walked, it should be transported on a trailer to the clinic if a vet cannot attend to the horse where it stands.

After a serious bout of tying-up the horse should be kept as comfortable as possible, adequate fluids should be provided to drink, and electrolytes, such as a scoopful of HUMIDIMIX^® morning and evening should be added to feed and the horse monitored under veterinary supervision. The horse should be given at least 4-6 weeks rest with only light work, depending on its recovery. All efforts should be made to find out the reasons for the tying-up in the first place, particularly as it is often a management related problem. The grain ration should be reduced and the horse exercised lightly each day until it is able to move freely again and ready to recommence training.

Prevention of tying-up

As mentioned earlier, tying-up is thought to be largely a management and nutrition related disease. Because the exact underlying metabolic causes are not fully understood, all possible avenues of treatment and preventative measures should be taken, with general management guidelines as follows:

• Always match the level of exercise to the grain intake. Ensure the horse is fit enough for the level of exercise proposed, and do not work an unfit horse too hard, too early in training.
• Nervy horses with a history of tying-up should be worked each day without a rest day, and if possible, measures should be taken to reduce their nervous disposition. Although it is common practice to give the horse one rest day a week, horses prone to tying-up (particularly if stabled), should be lunged or lightly worked under saddle EVERY DAY, even the day after racing.
• If the horse is to be given a light work day, the grain ration should be cut back to one-third on the night before the rest day, to match the energy level to the workload. Always take two days to restore full grain to horses prone to tying-up once regular exercise is continued.
• If the horse is not worked due to sickness, lameness or trainer ill health, the grain must be cut out on that particular day, and not reintroduced until the horse is able to recommence its exercise program.
• Where horses are travelling long distances to compete, provide dampened lucerne hay as a snack during the trip (reduces dust). During hot weather give a rehydration fluid such as 60-80 mL RECHARGE^® over the tongue or mixed in water as a drink, before and after travelling. If RECHARGE is given neat over the tongue fresh drinking water must be available.
• Always warm up at the trot for at least 10 minutes prior to fast work.

Feeding management to prevent tying-up

• Reduce Oats

  If a horse has a tendency to tie-up when fed oats, it is best to reduce the oats by at least half and replace with either steam-rolled barley or polyunsaturated cooking oil. One cup of oil contains the same amount of energy as six cups of oats and is particularly useful in very nervy fillies, as they tend to quieten down on oil-based rations.

  HINT: Clinical experience suggests that adding up to a cupful of polyunsaturated oil tends to reduce the incidence of "tying-up" in some horses, and it may be worthwhile incorporating this into the feeding program of a horse that has a history of "tying-up" on a regular basis.

When introducing oil, do so in a gradual manner over 7-10 days to allow time for the horse's digestive system to adjust to the higher fat diet. When oil is added to the ration as a source of energy, a dose of 1,000 IU vitamin E per day (e.g. 1 scoop of WHITE-E^®) should be fed to ensure proper metabolism and protection of the polyunsaturated oil in the diet.

• Replace Electrolytes

  Another important dietary factor is the daily provision of an electrolyte replacer, such as 1 scoop of HUMIDIMIX, morning and night. The addition of 1 tablespoon of Epsom Salts, morning and night, increasing in a stepwise manner over 4-7 days up to a maximum of 2 tablespoonfuls morning and night, appears to be of use in some horses that sweat heavily. Doing so tends to reduce their stride length and impulsion in the hind leg and back muscles as if "tying-up" during exercise.

• Vitamin E, Selenium and Chromium

  Supplementation with the trace minerals selenium and chromium (e.g. 56 g of FERAMO^® with CHROMIUM) and vitamin E (1 scoop of WHITE-E daily) may also reduce the incidence of tying-up in problem horses. In addition to tying-up, deficiencies of these nutrients can lead to loss of muscle strength and stamina.

• Muscle Buffers

  In practice, administration of 50 mL of NEUTRADEX^® in the feed daily, is helpful in preventing tying-up in some horses. NEUTRADEX contains an acid buffer which neutralises the lactic acid produced in muscles during hard or fast exercise. Lactic acid is the major factor which causes muscle soreness after exercise and in horses prone to tying-up, lactic acid accumulation may trigger a cramping attack.

  Tying-up is a common disorder that can range in severity from mild cramping to complete muscle "lock-up" which causes severe pain and a total inability to walk for several hours. In severe cases veterinary advice is essential to prevent serious muscle and kidney damage. Because the exact cause of tying-up is not fully understood, no single treatment is available. However, by following the management and feeding program detailed above, the problem can be prevented in about 90% of susceptible horses.