Azoturia is known by several different names including exertional rhabdomyolysis (ERM), tying-up, exertional myopathy and set-fast. It is a disease which is commonly seen in horses and typically affects their hindquarters and back. The condition is seen most in horses in training and occurs after a rest day on full rations followed by severe exertion. For this reason, it has also been called “Monday morning disease” from when carriage horses were worked after a rest day on Sunday. It is known however to occur in any horse regardless of rest.

What causes azoturia?

Damage to the muscles and tendons of the hindquarters and back gives rise to inflammation and pain in these regions. The actual reasons why horses develop this condition is not known. It appears that the disease can be related to excess energy intake with a low amount of exercise or to excess levels of certain salts in the blood.

What are the signs of azoturia?

In mild cases the first signs are of general stiffening or cramping of the hindquarters and back. Both hindlimbs are affected equally so the horse is unlikely to appear specifically lame. However, in more severe cases the horse may be unable to move and can even collapse; this may occur during exercise. Other signs may also be evident with affected horses showing colic signs such as “sweating up” and pawing at the ground.

How can I prevent azoturia?

Azoturia can be controlled by finding a balance between diet and exercise. Too much high energy feed with too little exercise can cause trouble. Your veterinary surgeon will be able to give you advice on appropriate regimes for both feeding and exercise as well as what to do if your horse has recurrent episodes.

What to do if I think my horse has azoturia?

First things first, keep the horse as still as possible and call the vet immediately. Further movement can cause more muscle damage, so stiller the horse can stay, the better. Food should be removed but the horse should be encouraged to drink. Your vet may administer anti-inflammatory painkillers and will assess the level of dehydration in the horse. If mild, then oral fluids containing electrolytes may be given, if severe then they may require intravenous fluids. The horse will need to be on box rest followed by paddock turnout and in hand walking before returning to work slowly. Your vet will be able to take a blood test to assess when the horse is fully recovered. If you'd like more information about ERM then contact us and we'll be happy to discuss it.