This is important in understanding the problem and planning proper treatment and prevention. The muscle cell membranes are broken allowing cell contents to spill into the blood stream. In severe cases the red coloured myoglobin from the muscles is released into the blood stream and expelled in the urine making it red. Myoglobin causes damage to the kidneys especially in dehydrated or sick horses.  

“Tying up” occurs during or closely after the horse has exercised. Horses are never tied-up when they first leave the box in the morning The condition only occurs after some form of exercise. 

Many risk factors for tying up have been identified including: work after a day’s confinement especially if the animals are fed a high grain diet on their day off; changing diet; excessive work in an unfit horse; genetic predisposition and sex. It has been shown that mares are more susceptible to tying up compared with geldings and colts.  

Low grade tying up is an important cause of poor performance. Horses start to move with “stiffness” particularly of the hindquarters when they are starting to tie up. During and after exercise watch your horse for muscle stiffness. After exercise horses should continue to walk freely even after they have been standing still to be untacked then walk off toward the wash bay. If your horse steps short with the hindlimbs after or during work, be suspicious that your horse is mildly tying up. When riding a horse that is starting to “Tie Up” the horse will feel less reluctant to move forward. If the horse is not returned to a walk, the willingness of the horse to move forward will decrease rapidly.

Confirm Diagnosis:

Blood test to assess muscle cell enzymes: AST and CK will confirm if your horse is tying up. It is best to know that you have a problem so that you can provide proper treatment and preventative programs.

Treatment of tying up

1. In severe cases when the horse will not move do not make the horse move any great distance. If the horse is a long distance from home a horse float / truck should be used for transport. If the horse is starting to tie up during an event, exercise should be stopped and the horse walked home as any further exercise only causes more damage to already injured muscle cells.

2. Anti-inflammatory drugs should be given as prescribed.

3. Fluid intake is very important; a saline drench is recommended for most cases. In some severely tied up cases we will administer intravenous fluids. This is particularly important for horses that have red coloured urine.

4. Vitamin E and Selenium supplementation will help the muscle cell membranes repair.

To prevent recurrence we recommend the following;

1. After a “Tying up” episode don’t work the horse faster than a walk until the muscle damage has resolved, ie. the AST and CK in the blood test are back to normal, this will take approximately one week;
2. Vitamin E and selenium, eg. Kynoselen at 20ml once a day for 3 days 
3. Roughage diet only with no or low grain for 1 week after a tying up episode, then when grain is reintroduced it must be gradually increased over at least a 2 week period. It is better to replace grain with a high oil diet.