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Comparison of High Definition Oscillometric & Direct Arterial Blood Pressure in Cheetahs

blood pressure measuring cheetahsblood pressure measuring cheetahs

Like domestic cats, older cheetahs frequently suffer from chronic kidney disease and since the kidneys play an important role in the regulation of blood pressure, we have suspected for some time that these cheetahs may also develop a chronic rise in blood pressure (hypertension).

Measuring blood pressure in a non-anaesthetised cheetah is however not without it's challenges. Automated non-invasive blood pressure monitors with an inflatable cuff, similar to those used in humans, can be applied to the tail or leg of a cheetah.
Stress-free measurements are critical, since any elevation in stress levels would also lead to an increase in blood pressure, resulting in inaccurate readings. Captive cheetahs can be trained to calmly have their blood pressure measured with no or only minor restraint, but we simply do not know how accurate these non-invasive blood pressure machines are in cheetahs.

The most accurate way of measuring blood pressure in any species is to place a catheter into a major artery. The catheter is attached to a transducer, which measures the pressure directly. Although this method is often used in anaesthetised patients, it is completely impractical in an animal that is awake.

We evaluated the accuracy of a new non-invasive high-definition ocillometric (HDO) device that is now being used in dogs, cats and horses. This study was carried out by Dr Emma Sant Cassia for her Master’s Degree in Wildlife Health through the Royal Veterinary College in London. She was supervised by Dr Adrian Tordiffe (during the 2014 and 2015 AfriCat Annual Health-checks in Namibia) and Dr Adrian Boswood.

After the cheetahs were anaethetised for their annual health checks, we collected simultaneous direct blood pressure readings from an artery on their hind leg and readings from the HDO device attached to their tail. The HDO device the changes in the pulse waves transmitted from the artery in the cheetah's tail as they are transmitted through the skin and detected by sensors in the cuff. Each set of readings was then statistically compared. We found that the HDO machine provided fairly accurate readings across a range of blood pressures. The accuracy of these readings could be further improved if we added a correction factor. These results were published in the Journal of Zoo and Wildlife Medicine.

Although the results looked very promising, we were not able to formally validate the HDO machine for use in cheetahs because the number of cheetahs we used in the study was too low.

At the 2015 annual health checks, Dr Sant Cassia returned to AfriCat to collect additional data to formally validate the HDO machine. We took the opportunity to also test the accuracy of HDO device when it is attached to the tail compared to when it is attached to a hind leg. This new data will be analyzed early in 2016 and hopefully be published before the 2016 health checks. If the HDO device is formerly validated, then we will start using it to collect blood pressure measurements in as many 'tame' cheetahs as possible. The early detection of hypertension in cheetahs will allow early intervention, improving the longevity and quality of life of these wonderful animals.

 

Full Report: Comparison of High-Definition Oscillometric and Direct Arterial Blood Pressure in Anesthetized Cheetahs. (PDF)

 

vet team health checks
Team of vets lead by Dr Tordiffe during the AfriCat Annula Healthchecks.
vet dr emma sant cassia
Dr Emma Sant Cassia (center).
blood pressure measuring cheetahs
Comparison of high-definition oscillometric and direct arterial blood
pressure measurement in anesthetized cheetahs.
automated non invasive blood pressure monitors2
Automated non-invasive blood pressure monitors with an inflatable cuff,
similar to those used in humans.
automated non invasive blood pressure monitors
Automated non-invasive blood pressure monitors with an inflatable cuff,
similar to those used in humans.
vet dr emma sant cassiaDr Emma Sant Cassia (center).

 

The authors would like to thank the AfriCat Foundation in Namibia (www.africat.org) and their staff for their help in the implementation of this project.

Dr Adrian Tordiffe BVSc MSc
Senior Lecturer (Pharmacology)
Department of Paraclinical Sciences
Faculty of Veterinary Science
University of Pretoria
Onderstepoort
South Africa

 

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