Blood pressure in free-ranging gray wolves (Canis lupus) immobilized with tiletamine and zolazepam

Abstract: This study aims to evaluate blood pressure measurements in immobilized free-ranging gray wolves (Canis lupus) in Sweden. Eight immobilized wolves (five adults and three juveniles) were included in this study. All wolves were darted from a helicopter with darts containing 250 milligrams of tiletamine and 250 milligrams of zolazepam. Immobilized wolves that showed signs of arousal, recieved a supplemental intramuscular injection of medetomidine. Systolic and diastolic blood pressure was measured non-invasively with an oscillometric device (Memoprint®, MediVet, Babenhausen, Germany) designed for dogs and cats. Rectal temperature, heart rate and respiratory rate were also measured. The hypothesis is that the wolves develop hypertension as a result of helicopter pursuit and the drug used. Three wolves were normotensive, four wolves had a moderate diastolic hypertenstion at one or more measuring point, and one wolf had a severe diastolic hypertension together with a mild systolic hypertension. None of the wolves had a moderate or a severe systolic hypertension. In conclusion, the effect on blood pressure was not as severe as previously thought. It was also noted that wolves who recieved an injection of medetomidine had a better anesthesia. In addition to this, other reference values for blood pressure and heart rates for free-ranging gray wolves should be used in future studies.