Hypocalcemia, or low calcium concentrations in blood, can be due to a wide variety of causes. Hypocalcemia impairs maneuverability of limbs and weakens bones. Severe hypocalcemia may also result in seizures, muscle fasciculations, ileus, tachycardia, synchronous diaphragmatic flutter, and ataxia. In horses, many cases of hypocalcemia are due to hypoparathyroidism or sepsis. However, there appears to be an inherited form of hypocalcemia in Thoroughbred foals for which the cause has not yet been determined. It is hypothesized that idiopathic hypocalcemia in Thoroughbred foals is due to a genetic mutation. Currently, this idiopathic disease has only been found to be present in Thoroughbreds. All clinically affected foals die or are euthanized due to the severe conditions of this disorder. Three orthologous genes in humans are hypothesized to be responsible for idiopathic hypocalcemia in horses. In joint effort with Dr. Gary Magdesian, our lab is currently in the works of investigating for a possible genetic variant responsible for the disease's phenotype in Thoroughbred foals.
Thoroughbred foals affected by idiopathic hypocalcemia are characterized by a variety of symptoms. The most common of symptoms are seizures, muscle fasciculations, cardiac arrhythmias, ataxia, stiffness of gait, tetany, increase in muscle tone, inability to chew, low calcium levels in blood, and, in some cases, low magnesium levels. The most facilitated and effective way to diagnose a Thoroughbred foal with hypocalcemia is to perform blood work and measure the calcium levels of the animal.
Are you concerned that your horse may have Idiopathic Hypocalcemia? Contact our lab for more information on how you can aid in equine genetic research.