Vascular pathology in phenylbutazone intoxicated horses.

This research study involves the examination of the vascular pathologies in three Thoroughbred geldings due to an overdose of phenylbutazone, finding that the drug caused degeneration in the small veins and other adverse effects.

Research Methodology

• The researchers used three mature Thoroughbred geldings for the study. These horses were administered with 13.63mg phenylbutazone per Kg of their body weight intravenously for a span of 3 days. This treatment was again repeated for one of the horses after 4 days.
• After 4, 7, and 10 days, various observations were made to study the effects of such high dosage of phenylbutazone on the horses. The effects were compared in horses who received the treatment once and the ones who got a double dose.

Findings and Interpretation

• The researchers found the small veins in all horses had yearned a state of degeneration due to the high dosage of phenylbutazone. The veins were either dilated or showed hyalin degeneration.
• This phlebopathy, a venous disorder, was considered as the primary side effect of phenylbutazone overdose. All the other observed side effects such as erythro- and leukodiapedesis (passage of blood cells through the intact walls of capillaries), submucosal edema (swelling beneath the mucous membrane), ulceration of the gastrointestinal mucosa, phlebothrombosis (venous thromboembolism), and significant changes in the hemogram and serum chemistry, were considered secondary.
• Thus, the researchers interpreted the vein lesions as the most significant pathological factor in phenylbutazone overdose.