Objective-To develop a dosage correlated with shoulder height (SH) in centi
meters for effective immobilization of free-ranging giraffes, using a combi
nation of medetomidine (MED) and ketamine (KET) and reversal with atipamezo
Animals-23 free-ranging giraffes.
Procedure-The drug combination (MED and KET) was administered by use of a p
rojectile dart. Quality of induction, quality of immobilization, and lime t
o recovery following injection of ATP were evaluated. Physiologic variables
measured during immobilization included Pao(2), Paco(2), oxygen saturation
, end-tidal CO2,`blood pH, indirect arterial blood pressure, heart and resp
iratory rates, and rectal temperature.
Results-Sixteen giraffes became recumbent with a dosage (mean +/- SD) of 14
3 +/- 29 mug of MED and 2.7 +/- 0.6 mg of KET/cm of SH. Initially, giraffes
were atactic and progressed to lateral recumbency. Three giraffes required
casting with ropes for data collection, with dosages of 166 +/- 5 mug of M
ED and 3.2 +/- 0.6 mg of KET/cm of SH. Four giraffes required administratio
n of etorphine (n = 2) or were cast with ropes (2) for capture but remained
dangerous to personnel once recumbent, precluding data collection. In gira
ffes successfully immobilized, physiologic monitoring revealed hypoxia and
increased respiratory rates. Values for Paco(2), end-tidal CO2, and heart r
ate remained within reference ranges. All giraffes were hypertensive and ha
d a slight increase in rectal temperature. Atipamezole was administered at
340 +/- 20 mug/cm of SH, resulting in rapid and smooth recoveries.
Conclusions and Clinical Relevance-Medetomidine and KET was an effective im
mobilizing combination for free-ranging giraffes; however, at the dosages u
sed, it does not induce adequate analgesia for major manipulative procedure
s. Quality of induction and immobilization were enhanced if the giraffe was
calm. Reversal was rapid and complete following injection of ATP.