Effects of flunixin meglumine on selected clinicopathologic variables, and serum testosterone concentration in stallions after endotoxin administration.

The research study observes the effects of flunixin meglumine (a painkiller and anti-inflammatory drug) on horses post intravenous administration of endotoxin. The results suggest that while flunixin meglumine manages some endotoxin-induced symptoms, it does not affect the decrease in white blood cells (leukocytes) and has a delayed influence on testosterone levels.

Design and Execution of the Study

• The research involved eight clinically healthy stallions (male horses).
• Four of these stallions were given a dose of endotoxin or lipopolysaccharides (LPS), specifically from the variant of Escherichia coli known as 055:B5. This dose was administered intravenously at a rate of 0.3 micrograms per kilogram of body weight.
• The other four stallions were given a dose of flunixin meglumine (FM), an injectable drug that acts as an anti-inflammatory agent and is often used for pain relief in animals. This dose was also given intravenously, 5 minutes after the endotoxin administration, and was measured as 1.1 milligrams per kilogram of body weight.

Observations After Endotoxin Administration

• The reactions observed in the stallions after the endotoxin administration included fever, represented by a rise in rectal and scrotal skin temperatures, an increased heart rate (HR), and leucopenia, which represents a decrease in leucocytes or white blood cells.
• The endotoxin administration also caused fluctuations in the testosterone levels in the blood serum of the stallions. There was an initial decrease observed at 3-24 hours post-injection and a subsequent increase at 48-72 hours post-administration.

Effects of Flunixin Meglumine Treatment

• The study found that the administration of flunixin meglumine successfully prevented the endotoxin-induced rise in rectal and scrotal skin temperatures, as well as the increased heart rate.
• However, the administration of flunixin meglumine did not prevent the decrease in leucocytes.
• The study also observed flunixin meglumine’s effect on the changes in testosterone levels. The drug seemed to only significantly affect the later changes in testosterone concentration (at 24 to 72 hours post endotoxin administration), but not the initial decrease.