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Windhoek - How do you stop a cheetah overheating when it's darted?
Hint: you need more than cold water.
Wildlife vets have known for some time that one of the biggest threats to cheetahs when they're put under anaesthetic is hyperthermia.
Now vets working at The AfriCat Foundation's unique facility for rescued big carnivores in Okonjima, Namibia have developed what appear to be extraordinarily effective ways to avoid or bring down dangerously-high temperatures in cheetahs that have just been immobilised.
That way, they can still get the root canals done.
Cheetahs aren't the only animals whose body temperatures can rise significantly when they're anaesthetised, says the University of Pretoria's Dr Adrian Tordiffe who's been working with the cheetahs in the AfriCat facility for some time.
Capture-induced hyperthermia has been shown to affect lions, antelopes and even brown bears, Tordiffe told News24. He has seen rectal temperatures in lionesses, for example, soar from a "normal" 38.5 degrees celsius to 40 and even 41 degrees soon after they've been darted.
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But cheetahs' temperatures can go up to as high as 43 degrees. If left unchecked, that can lead to organ damage and death.
The reason for these alarming surges in body temperature, which have traditionally been treated with lots of water and ice?
Stress, mostly.
Working on the premise that cheetahs get stressed when they see the vet or the capture team on its way, Tordiffe and his colleagues at AfriCat have been experimenting with ways of trying to take them by surprise.
In 2015, they started using canvas screens to shield the "catch camps". The screens had darting "windows" cut into them, so that vets could dart the cats without being seen.
It wasn't a total success.
Says Tordiffe: "We soon realised that some cheetahs were actually more stressed by the presence of the canvas screens as they had not been exposed to them before and when the wind blew, the canvas flapped around creating additional noise and stress."
Traditional cooling methods
Now what the vets at AfriCat do is stealthier still: they hide (with their darting guns) on the vans normally used to take food to the cheetahs in the reserve.
The cheetahs think food is on its way - and they don't get stressed. In fact, during annual health checks and dental ops for the cats this year, "these cheetahs all had normal rectal temperatures after they were darted", said Tordiffe.
But whatever efforts are taken, sometimes cheetahs that Tordiffe has to treat still get stressed before they're darted.
While ice-cold water might bring down the temperature of the animal's skin, it doesn't bring down its core temperature nearly as quickly.
The answer? Traditional cooling methods, yes. But also drugs - fast. Tordiffe and his colleagues have started using a gas anaesthetic on affected cheetahs plus an antidote to medetomidine, one of the drugs used in the dart. The antidote makes the blood vessels in the skin and muscles dilate, speeding up the cooling process.
Very high initial temperatures
Explains Tordiffe: "Cheetahs with very high initial temperatures recovered without any lasting effects when this strategy was used."
Sadly, cheetahs in the wild still die every year during translocations or when they've been darted. Tordiffe and AfriCat are hoping to carry out more research to work out exactly why that is: is it just because of severe overheating or might it be due to the effects of the release of acute stress hormones?
For now that is still not clear.
But in a controlled environment like the AfriCat facility, Tordiffe says the methods he and his colleagues have developed to combat pre-darting stress and hyperthermia give the vets confidence to deal with even the most severely overheated cheetahs.
There's no escaping that root canal, big guy!
