Effects of acetylpromazine, xylazine, and vertical load on digital arterial blood flow in horses.
Palmar digital arterial blood flow was measured in 6 conscious, standing horses, using surgically placed perivascular ultrasonic flow probes. The effects of 2 dosages of xylazine (0.55 and 1.1 mg/kg of body weight) and of 3 dosages of acetylpromazine (0.01, 0.02, and 0.04 mg/kg), as well as the effect of vertical load, on digital blood flow were evaluated. Intravenous administration of xylazine induced a significant (P < 0.05), transient decrease in digital blood flow. Intravenous administration of acetylpromazine induced a significant (P < 0.05), prolonged increase in digital blood flow. Correlation between vertical load and digital blood flow was found. The results of this study indicate that use of acetylpromazine may be beneficial in clinical treatment of horses with reduced digital blood flow. Xylazine, on the other hand, may exacerbate ischemic conditions of the digit and should be used with caution.
Hunt
R J
RJ
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602-7385.
Brandon
C I
CI
McCann
M E
ME
D000075:Acepromazine / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D005528:Foot / Q000098:blood supply*; D006736:Horses / Q000502:physiology*; D008297:Male; D009919:Orchiectomy; D011187:Posture; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology*; D014991:Xylazine / Q000494:pharmacology*
D014991:Xylazine; D000075:Acepromazine