Measuring for Clotting Disorders Might Help Predict Outcome for Colicky Horses

A simple blood test to measure plasma D-Dimer concentration in horses with colic might help veterinarians predict severity and outcome of cases, as concentrations are higher in horses with severe gastrointestinal (GI) disease, according to a group of University of Barcelona researchers.

D-Dimers are small protein fragments that are found in blood after it clots. Veterinarians often measure D-Dimer levels when they believe horses suffering from ailments such as severe GI disorders and sepsis are at risk for developing clots. But recently Luis Monreal, DVM, PhD, Dipl. ECEIM, and colleagues confirmed in a prospective observational clinical study that levels are also higher in horses with specific severe colic signs, and that these horses had more clotting disorders than their colicky counterparts.

Researchers recorded the blood levels of D-Dimer in 493 horses admitted to the University's hospital with clinical signs of colic (both medical and surgical cases), the eventual diagnosis of each horse, and if the horse recovered. They found that horses with diagnoses of enteritis (inflammation of the intestinal tract) or peritonitis (inflammation of the membrane lining in the abdomen) had significantly higher levels of D-Dimer than horses with other diagnoses. Their findings also revealed that study horses that died as a result of any type of colic had the highest blood levels of D-Dimer.

"The most severe forms of GI diseases--marked by inflammatory and ischemic (lack of blood flow) problems--produce a strong activation of the coagulation system," Monreal explained.

Measuring D-Dimer in colicky horses will help veterinarians determine if particular animals are at risk of having a clotting disorder, such as horses suffering from proximal enteritis, diarrheas, peritonitis, hernias, or volvulus and other causes of strangulated bowel. If the test results reveal high levels present in the blood, the veterinarian can administer anti-coagulants, such as heparin, which could prevent complications (for example, thrombophlebitis--inflammation of the blood vessel wall which often results in clots) and minimize the development of small clots in other organs of the body.

In a previous study Monreal's research group found small blood clots in the lungs, kidneys, liver and other organs of 93 colicky horses with disseminated intravascular coagulation-a severe clotting disease. These horses did not survive, and the blood clots proved to be a factor in their deaths, he noted.

"Studies have shown that horses with gastrointestinal disorders that were associated with severe imbalances in the coagulation system had a prolonged hospital stay and statistically less chance of survival than other horses with the same diseases but without coagulation problems," Monreal explained.

The study, "Association of admission of plasma D-Dimer concentration with diagnosis and outcome in horses with colic," was published in the November/December issue of the Journal of Veterinary Internal Medicine. The abstract is available on PubMed.

About the Author

Marie Rosenthal, MS

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