Anti Drug Giraffe Treatment
A combination of etorphine and azaperone provided a successful immobilisation and translocation for nine free-ranging Masai giraffes. The azaperone, which has sedative and anti-anxiety properties, also induces vasodilation that counterbalances opioid hypertension in this species.
Restraint quality was excellent in six of the nine giraffes, and one required caution due to occasional but potent kicks. Arterial blood gas analyses were recorded from all individuals.
A high number of giraffe mortalities during capture, immobilisation and translocation are due to common mistakes, human error or unforeseen risks. The awkward anatomy of the animal and their high-rise posture make them particularly susceptible to injury and death.
Blood gas analyses showed that all giraffes experienced a metabolic acidosis, possibly caused by an increase in lactic acid levels and decreased values of bicarbonates. This may result in excessive exhaustion, stress and hyperthermia.
The giraffes were successfully captured on 43 occasions to collect various biological data. Knockdown times for the different drugs and drug cocktails were recorded and analysed. This information could help to shape future standard operating procedures. In the present study, etorphine and the sedative combination butorphanol-azaperone-medetomidine (BAM) were used. This combination has the advantage of a short knockdown time. However, its side effects such as tachycardia are problematic in free-ranging restrained giraffes. This is likely because etorphine stimulates catecholamine release, which causes a hypertensive response in this species . This effect can be overcome by early reversal with naltrexone.
A team of passionate individuals from across the world worked together to bring this project to life. This included veterinary staff from Cleveland Metroparks Zoo and Colorado State University College of Veterinary Medicine, along with the ever-famous Dr Pete Morkel, renowned for his extensive knowledge on megaherbivore capture and transport.
During the giraffes’ capture and transport, blood gas readings were collected and analysed in real time using an iStat analyser to monitor and assess physiological function throughout the process. This is important as giraffes are susceptible to both overexertion and opioid-induced side effects.
All giraffes were darted with a CO2 pressurised dart syringe, and once they reached lateral recumbency, were manually restrained by the veterinary team. Six giraffes were rated excellent for their restraint with minimum fight reactions, and one giraffe required caution due to occasional but potent leg kicks. Heart rate was monitored and remained within the resting giraffe range during the entire process. This was despite the use of an opioid-based protocol with etorphine and azaperone, which are known to increase heart rate.
Few studies report physiological variables and blood gas analyses in free-ranging restrained giraffes. Heart rate in this study slightly increased with time, however, it remained within the range of resting giraffe heart rates measured by telemetry or in trained unanaesthetised giraffes. The reason for this increase is likely catecholamines release by etorphine which induces tachycardia in many species. This is in contrast to alpha2-agonist-based protocols which usually cause bradycardia .
Arterial blood gases analysed at T2 in this study indicate that the giraffes were immobilised well and that they recoverd quickly. Despite a low excitement score in one giraffe (rated as 1 out of 4) and acidosis in a couple of individuals, cardiorespiratory function was adequate. This is an important finding, as a lack of respiratory compensation can lead to uncompensated acidosis and devastating homeostatic consequences, such as capture myopathy in giraffes. This indicates that the azaperone-etorphine combination used here, with its short recovery times and high quality of restraint, is a promising approach to reduce manipulation stress during translocations of free-ranging giraffes.
During immobilisation, capture and transportation operations giraffes are at high risk of death . Common mistakes, human error and unforeseen risks combined with their awkward anatomy contribute to this. Their sensitivity to drugs, long resting times and large respiratory dead space also increases the risk of anaesthetic problems .
Incorrect dart placement (on the shoulder rather than in the rump) or under-dosing can delay the knockdown effect, and result in the animal running away. This can lead to exhaustion, overheating, hyperthermia and capture myopathy .
Many of us will remember Healthy Harold, the giraffe that would pull up at primary schools in his Life Education van and talk about eating healthy food. Now the iconic giraffe is being used to teach our young people about the dangers of methamphetamine use. Four environmental and advocacy groups have today filed a lawsuit to get the federal government to start protecting giraffes. The suit cites population declines and ongoing threats from habitat loss, land conversion and poaching.