Alterations in coagulation and hemograms of horses given endotoxins for 24 hours via hepatic portal infusions.

The research article explores how prolonged uptake of endotoxin in horses affects their behavior and alters their coagulation and hematologic values, highlighting an increase in hoof discomfort and a drop in hoof temperature as a result of the endotoxins affecting the horse’s gastrointestinal system.

Introduction and Methodology

• The researchers aimed to establish a model for studying the effects of prolonged endotoxin uptake, specifically its impacts on gastrointestinal disturbances in horses.
• The study involved the catheterization of the hepatic portal vein of seven horses through flank incisions to allow the chronic hepatic portal infusions of a type of endotoxin, known as lipopolysaccharide (LPS).
• The LPS was infused at a rate of 1 microgram per kg of body weight per hour for a duration of 24 hours. Two of the horses were initially infused with saline solution for 12 hours before LPS infusions were given.

Findings and Observations

• It was observed during the study that the LPS had significant effects on the behavior and hematologic and coagulation values of the horses.
• The first hour after the infusion was the most crucial period for the LPS-infused horses. However, by the fourth hour, the horses seemed to become refractory or unresponsive to the continued infusion of LPS.
• All horses collapsed within the first hour of infusion, yet there was no accompanying drop in blood pressure (hypotension).
• A decrease in polymorphonuclear leukocytes, specifically neutrophils, was observed during the first hour. This was accompanied by a shortening of recalcification tests, one-stage prothrombin time, and activated partial thromboplastin time.
• There was also an increased concentration of circulating fibrinogen and fibrin degradation products in the blood of the horses.
• All of the horses that were infused with LPS exhibited signs of discomfort in their hooves and either stood with all four feet together under their body or continually shifted their weight from one front foot to the other.
• The horses also experienced a significant decrease in hoof temperature by approximately 3 degrees Celsius, which lasted for the duration of the experiment.