Furosemide-induced changes in plasma and blood volume of horses.

This research investigates the effects of furosemide, a diuretic drug, on the blood and plasma volumes in horses, observing a significant and rapid reduction in plasma volume following the administration of this drug.

Research Methodology

• The research was conducted on ten horses, six of which were intact and the remaining four which had undergone splenectomy, i.e., they had their spleens removed.
• The drug furosemide was administered to the horses at a dosage of 1 mg/kg body weight intravenously.
• The impact of this drug was measured using various techniques such as Evans blue dye dilution, hematocrit, and evaluating the concentrations of hemoglobin and plasma total solids.

Observations and Findings

• Post-administration of furosemide, the body weight of the intact and splenectomized horses dropped by 33.6 +/- 3.3 g/kg and 33.7 +/- 0.8 g/kg respectively after 4 hours.
• Estimations of the plasma volume was done by Evans blue dye dilution, and it was found to have decreased by approximately 8.3 +/- 3.3% (mean +/- SE) within 4 hours of the drug being administered.
• First signs of plasma volume reduction were noticeable within 5-10 minutes of furosemide administration, with the greatest reduction (13.0 +/- 0.8%) being seen 15-30 minutes following dosing.

Conclusions

• This study underscores that the administration of furosemide leads to significant and immediate reductions in the plasma volume in horses.
• It is observed that the decreases in plasma volume caused by furosemide only partially resolve even 4 hours post-administration. Thus, it implies prolonged effect of the drug on the horses’ blood circulation system.