Objective-To determine sedative, analgesic, and basic cardiovascular e
ffects of xylazine administered to pigs. Animals-6 two-month-old Landr
ace x Large White pigs. Procedure-Xylazine was administered IV at incr
easing dosages (1, 2, 4, 8, and 16 mg/kg of body weight) to otherwise
unmedicated, conscious pigs, and the aforementioned effects were deter
mined before xylazine administration and 2, 5, 10, and 15 minutes late
r. Then a higher xylazine dosage was given after the 15-minute measure
ments were taken. Results-None of the xylazine dosages induced suffici
ent analgesia to prevent painful response to tail clamping; considerab
le excitation with vocalization and without appreciable sedative effec
t was observed at ail dosages. At lower dosages, cardiovascular effect
s were characterized by bradycardia and biphasic blood pressure respon
se; initial hypertension was followed by hypotension. At higher dosage
s, severe hypotension with moderate bradycardia was followed by marked
bradycardia and return to normal baseline values or slight increase i
n blood pressure. Conclusion-Xylazine did not induce adequate sedative
or analgesic effects in pigs at any dosage tested; however, cardiovas
cular effects were considerable. These effects of xylazine differ from
those observed in other domestic species.