Effect of furosemide on physiologic variables in exercising horses.
Twelve horses (6 Standardbreds and 6 Thoroughbreds) received IM injections of furosemide (250 mg) or physiologic saline solution and performed standard exercise tests, to assess the effects of furosemide and breed on blood gas values, PCV, plasma lactate concentration, and heart rate during exercise. After furosemide administration, arterial and venous blood pH values were significantly (P < 0.05) increased. Partial pressures of O2 and CO2 in arterial blood and of CO2 in venous blood (PaO2, PaCO2, and PVCO2, respectively) were unaffected by furosemide treatment, whereas venous partial pressures of O2 (PVO2) were significantly (P < 0.05) less during exercise after furosemide treatment, suggesting an increase in oxygen uptake by the exercising muscles or a change in cardiac output. A significant (P < 0.05) difference was found between Thoroughbred and Standardbred values for arterial and venous pH, PaO2, PaCO2, plasma lactate concentration, and heart rate, suggesting that Standardbreds exercised at a relatively higher work rate than did Thoroughbreds.
Harkins
J D
JD
Department of Clinical Sciences, Veterinary Medical Teaching Hospital, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853.
Hackett
R P
RP
Ducharme
N G
NG
D000818:Animals; D001800:Blood Specimen Collection / Q000379:methods / Q000662:veterinary; D001810:Blood Volume / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output / Q000187:drug effects; D005080:Exercise Test / Q000662:veterinary; D005665:Furosemide / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D006736:Horses / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects; D010313:Partial Pressure; D010805:Physical Conditioning, Animal
D007773:Lactates; D002245:Carbon Dioxide; D005665:Furosemide; D010100:Oxygen