The effects of a modified combination of th ree agents were assessed in the
case of 3 experimental horses and 12 patients of a clinic. After being pre
-medicated with a small dose of butorphanol and detomidine, each horse was
put under anaesthetic by a rapid I.V. infusion (0.5 ml/kg) of a compound co
ntaining 100 mg of glycerol guaiacolate, 2 mg of ketamine, and 1 mg of xyla
zine in 1 mi of 5% dextrose (mixture A). The horses went under slowly and q
uietly: no traumatic complications were noted, Anaesthesia was maintained b
y continuous I.V: administration of the same drug composition but of higher
concentration, In 1 mi of 5% dextrose: 200 mg of glycerol guaiacolate, 6 m
g of ketamine, and 3 mg of xylazine (mixture B). Pilot studies had revealed
that the infusion of mixture B at a rate of 3.5 ml/500 kg/h produced adequ
ate and useful surgical tolerance. The average duration of the anaesthesia
was 56 min (+/-12). The proposed technique provides satisfactory, uneventfu
l induction, stable anaesthesia and smooth recovery. After anaesthesia the
horses were recumbent for a short time (24 min +/-12) without any signs of
excitement. In twelve of fifteen cases of anaesthesia the horses stood up a
t the first attempt. Respiratory and heart rate stayed within physiological
ranges. According to the authors, this kind of procedure is relatively ine
xpensive and easy. That is why it gives an opportunity for the broader use
of socalled total intravenous anaesthesia (TIVA) in horses.