Tying-Up

• What is tying-up? ↓

  Tying-up is also known as azoturia, set-fast or Monday morning disease and involves the cramping, and resultant pain, mainly of the muscles of the hindquarters and back.  Episodes can vary in severity and can become a recurrent, chronic problem.  We now know that tying-up is technically either Equine Rhabdomyolysis Syndrome (ERS) or equine Polysaccharide Storage Myopathy (PSSM), both of which result in similar symptoms but for different reasons. 
   
  Equine Rhabdomyolysis Syndrome (ERS) involves the rupture (lysis) of muscle cells, resulting in the release of their contents into the blood stream.  This is thought to occur as a result of a calcium imbalance in the cells but the causes of this are yet to be fully understood.
   
  Polysaccharide Storage Myopathy (PSSM) is caused by an abnormal build up of glycogen, the polysaccharide storage form of glucose which is stored in the muscles and used to fuel muscle contraction. 
   
  Read more about tying-up in the following articles:
   
  All Tied-Up
  Feeding and Managing a Horse with Polysaccharide Storage Myopathy

   

• What are the symptoms of tying up? ↓

  The symptoms of tying-up can range from mild stiffness, or unexplained slight lameness, to an inability to move and the main difference between ERS and PSSM is that PSSM will occur very early on in an exercise session, in walk even, while ERS usually comes on during or at the end of more strenuous exercise.
   
  In severe cases the muscles of the back an quarters will spasm and may be hard and painful to the touch and even bulge.  The horse is likely to sweat, due to the pain, and may even attempt to lie down or paw at the ground.  He should not be made to move until he feels comfortable enough to do so and, in cold weather, should be kept warm.  The vet should always be called if tying-up is suspected.
   
  Horses who’ve suffered an episode of ERS will have dark discoloured urine as the body extracts the myoglobin, from the broken down muscle cells, from the bloodstream.  Vets usually take blood and test for levels of enzymes which are released when muscle cells are damaged.
  

• What are the causes of tying-up? ↓

  PSSM has been shown to have genetic associations and to occur in certain breeds of horses, whilst horses who suffer from ERS may be predisposed to the condition but no genetic link has been established.  Whilst ERS has traditionally been blamed on dietary factors - namely too much starch, hence “Monday morning disease”, as working horses were prone to tying-up if they had been rested on Sunday with full rations – it has now been acknowledged that there are many other contributory factors. 

  Simply working a horse beyond its level of fitness can bring on an episode as can underlying lamenesses or back problems.  Mares and fillies are often prone, indicating a hormonal involvement, and stressy horses are also more likely to tie-up recurrently.  Dehydration and mineral or electrolyte imbalances are also implicated.
   
  Read more about the possible causes:
   
  All Tied-Up
  Feeding and Managing a Horse with PSSM

   

• What can I feed a horse prone to tying up? ↓

  In the immediate aftermath of an attack, the vet will probably recommend that hard feed is withdrawn and the horse fed just forage and water.  Whilst feed may not be directly implicated in all cases of ERS, diet is most definitely key to the management and prevention of further episodes of both ERS and PSSM, with the aim being to reduce, and for PSSM horses, cut out, the starch content of the diet.
   
  Part of the long term management of horses prone to ERS is to ensure a fully balanced diet is fed at all times to ensure optimum levels of vitamins, minerals, antioxidants and electrolytes.  This can be achieved by always ensuring the recommended amount of an appropriate compound feed, like Ease & Excel, or Ease & Excel Cubes, is fed and, when amounts are reduced, that the diet is topped up with Performance Balancer  to ensure vitamin and mineral levels are kept at an optimum.
   
  For working horses who require more calories than forage alone can provide, highly digestible fibre products and oil represent “safe”, non-starch additional energy sources.  For horses who have suffered a one-off episode or for whom a management regime has been established which has meant they have not tied-up for some months, a reduced starch, high oil, high fibre feed, like All-Round Endurance Mix or Slow Release Condition & Competition Mix, is often useful.
   
  Fully balanced low starch feeds are:
  
  Keep Calm
  Ease & Excel

  Ease & Excel Cubes
  
  Fully balanced reduced starch feeds are:
  
  All-Round Endurance Mix
  Slow Release Condition & Competition Mix
  
  Sources of non-starch calories include:
   
  Outshine
  Speedi-Beet
  Fibre-Beet
  Alfalfa Plus Oil
  Alfalfa Blend
   
  For further practical feeding advice, read the following:
   
  All Tied-Up
  Feeding and Managing a Horse with PSSM