Effects of intravenous administration of dimethyl sulfoxide on cardiopulmonary and clinicopathologic variables in awake or halothane-anesthetized horses.
OBJECTIVE
To evaluate the cardiopulmonary and clinicopathologic effects of rapid IV administration of dimethyl sulfoxide (DMSO) in awake and halothane-anesthetized horses.


METHODS
Prospective study.


METHODS
6 adult horses.


METHODS
Horses received IV infusion of 5 L of a balanced electrolyte solution with and without 1 g/kg (0.45 g/lb) of 10% DMSO solution when they were awake and anesthetized with halothane (4 treatments/horse). Arterial and venous blood samples were collected immediately before and at intervals during or after fluid administration and analyzed for blood gases and hematologic and serum biochemical variables, respectively. Heart rate, respiratory rate, and arterial blood pressure variables were recorded prior to, during, and after fluid administration.


RESULTS
After administration of fluid with or without DMSO, changes in measured variables were detected immediately, but most variables returned to baseline values within 4 hours. One awake control horse had signs of anxiety; agitation and tachycardia were detected in 2 awake horses administered DMSO. These clinical signs disappeared when the rate of infusion was reduced. In anesthetized horses, increased concentrations of WBCs and plasma fibrinogen and serum creatine kinase activity persisted for 24 hours, which was related to the stress of anesthesia more than the effects of fluid administration.


CONCLUSIONS
Infusion of 5 L of balanced electrolyte solution with or without 10% DMSO induced minimal changes in cardiopulmonary function and clinicopathologic variables in either awake or halothane-anesthetized horses. Stress associated with anesthesia and recovery had a greater influence on measured variables in anesthetized horses than fluid administration.
Lin
Hui-Chu
HC
Department of Clinical Sciences. College of Veterinary Medicine, Auburn University, Auburn, AL 36849-5522, USA.
Johnson
Christopher R
CR
Duran
Sue H
SH
Waldridge
Bryan M
BM
D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage*; D018685:Anesthetics, Inhalation; D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004121:Dimethyl Sulfoxide / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D006221:Halothane; D006339:Heart Rate / Q000187:drug effects; D006736:Horses / Q000502:physiology*; D007262:Infusions, Intravenous / Q000662:veterinary; D011446:Prospective Studies; D011897:Random Allocation; D012119:Respiration / Q000187:drug effects
D018712:Analgesics, Non-Narcotic; D018685:Anesthetics, Inhalation; D006221:Halothane; D004121:Dimethyl Sulfoxide