Gamma scintigraphic analysis of the distribution of perfusion of blood in the equine foot during black walnut (Juglans nigra)-induced laminitis.

The research presents a study on the effect of an extract of black walnut (Juglans nigra) on the perfusion of blood in the foot region of horses suffering from acute laminitis. It reveals that the onset of laminitis leads to a decrease in blood perfusion to specific areas of the foot, and this effect is mitigated by the administration of prazosin.

Research Context

• The research study is centered on acute laminitis in horses, which is primarily a condition causing foot pain in these animals.
• Laminitis was induced in the horses through intragastric dosing with an aqueous extract of black walnut (Juglans nigra) heart-wood.
• The research employed gamma scintigraphy, a diagnostic technique, to analyze and quantify the distribution of blood perfusion in the equine foot before and after the laminitis induction.

Research Methodology

• The scientists conducted the study on 12 horses suffering from laminitis chiefly in the forefeet at 12 hours post intragastric dosing.
• They utilized 99mTc-labeled macroaggregated albumin to quantify blood perfusion rates in the foot region through gamma scintigraphy.
• The horses were studied and perfusion quantified at Timelines: initial baseline, 12 hours after extract administration, and finally at 84 hours after extract administration.
• Six of these horses (7 to 12) were given a single dose of prazosin immediately after the second scintigraphy stage and before the third scintigraphy stage to observe its effects.

Research Findings

• The researchers found that perfusion to the forefoot of horses decreased versus perfusion to the whole distal portion of the forelimb following the development of acute laminitis.
• At the onset of laminitis, blood flow also decreased to the dorsal laminar and coronary corium regions as compared to its flow to the distal portion of the forelimb.
• The researchers observed that this laminitis-related lack of perfusion wasn’t experienced by horses that had received prazosin treatment.
• Comparison with baseline images revealed an increase in blood flow to the dorsal lamina in relation to the distal part of the limb at 84 hours post-dosing. However, the prazosin treatment did not impact this increase.