Press Office

Fluid control leaves primates unaffected

Fluid control leaves primates unaffected, study finds

Published on: 28 September 2016

An examination of the use of fluid rewards in primates has found that the animals are largely unaffected by controlled water access.

Scientists at Newcastle University report in the journal eNeuro their findings on the effects of fluid control on primates within limits widely used worldwide, and more restrictive than normally granted nowadays in the UK. This provides the first significant scientific evidence as to whether there are potential welfare consequences - an area that has in the past been of concern.

Studies often use awake, behaving primates to investigate cognitive and neural processes. These require the tasks to be repeated many times to achieve adequate data of high enough quality. Fluid control within exacting standards laid down by the Home Office can be used as a motivational factor.

The scientists report on physiological and behavioural changes induced by fluid control, assessed in four primates over 16 weeks. These were compared to results when the monkeys had free access to water and where possible, to a control group at another site.

The scientists found that widely used fluid control protocols did not result in physiological changes of concern to animal welfare.

Similarly, there was no evidence of fluid control increasing anxiety, as measured through behaviour changes such as body shaking, self-grooming or yawning.

No physiological changes

Alexander Thiele, Professor of Visual Neuroscience, explained: "There were no physiological changes that could give rise to short or longer term welfare concerns. This should not be a surprise as the ecology of the primates means that in the wild they go for days without water intake.

“Behavioural changes were equally very limited. While some changes suggested that welfare might be mildly compromised by water control, other even suggested the opposite."

Work on primates at Newcastle University is only carried out where no suitable alternatives can be found and under the strict control of the Home Office and ethics committee.

The University works to replace, reduce and refine the use of animals in research and this study was funded by the NC3Rs.

Most research primates are macaques or marmosets. They are used in relatively small numbers and make up around 0.1% of research animals but they have been important in many important medical advances; for example the polio vaccine, life support systems for premature babies, and deep brain stimulation for Parkinson’s Disease.

REFERENCE:  Physiological, Behavioural, and Scientific Impact of Different Fluid Control Protocols in the Rhesus Macaque (Macaca mulatta). eNeuro. DOI:




Latest News