by Annalou Mack

Created on: June 08, 2010

The noises that a horse makes that sound like hiccups is thumps or Synchronous Diaphragmatic Flutter (SDF).  There is a thumping noise in the horse’s abdomen which may or may not be serious. It seems that his entire body is convulsed with mild rhythmic spasms in time with the beating of his heart.  He may also show signs of stiffness and depression. If he is dehydrated and has a high temperature, you need to call the vet.

The condition called thumps is caused by a change in blood ph. and blood calcium concentrations.  It can be a mild problem of short duration or it may be a life threatening electrolyte imbalance.  Thumps sometimes occurs after a hard workout when significant fluid has been lost through sweating.  But it can have other causes such as: diarrhea, heavy lactation, overeating, and blister beetle toxicosis.

A horse with thumps may exhibit mild contractions that can only be felt under your hand, but in severe cases it can be observed from several feet away.  The contractions occur at the same time as the heart beats and may be on either side of the horse.  When the contractions can be observed from a distance, it is a sign that the horse is in severe metabolic distress.  These are signs of dehydration and massive loss of electrolytes.

The function of the nervous system is compromised when the bloodstream is depleted of salt ions.  The nerve that runs across the heart to the diaphragm muscle causes that muscle to contract in time with the heart beat, making the thumping flutter.

When you first hear signs of thumps in your horse, stop the exercise immediately and call your vet.  If the thumps are from mild exhaustion, cooling the horse and giving him access to water and food may be all that is needed.  Do not let the horse drink copious amounts of water until he has cooled down, as that can cause founder. 

If the horse is suffering from severe exhaustion, he will not be interested in food and water.  He may also have an elevated temperature. In this case, wait until the vet arrives. He will be able to correct the fluid and electrolyte imbalances. He may treat your horse with IVs containing calcium and fluids to restore blood calcium levels.  Other electrolyte levels, such as magnesium, potassium, sodium and chlorine should also be checked.

Above all, do not ignore the problem. If thumps is not treated, it can lead to founder, colic, heat exhaustion or collapse.  After your horse is treated, take precautions to prevent a re-occurrence. Do not allow the horse to become overheated, provide plenty of fresh water and see that he is fed proper nutrition.  An electrolyte supplement may be recommended.

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