It seems that people aren't the only ones who've learned to grin and bear it when faced with an unpleasant task: New study results suggest that even if horses act like they don’t mind body clipping, they could still find it to be stressful.
“Quiet acceptance (in well-trained horses) has been rewarded in the past and will tend to override their desire to escape and avoid whatever we are doing to them,” said Carol Hall, PhD, researcher and principal lecturer at Nottingham Trent University, in the U.K.
In a study led by Kelly Yarnell, a PhD candidate under Hall’s direction, researchers evaluated 10 horses (five described as “compliant” during clipping and the other five described as “noncompliant”) as they were “sham clipped”—meaning the researchers ran running clippers over the horses' bodies, but the blades were not active. The researchers observed the horses' behaviors, heart rate, salivary cortisol levels, and eye temperatures before, during, and after the sham clipping sessions. Thermographic eye readings can reveal instantaneous changes in stress level without touching the horse, unlike salivary sampling, Hall said.
True to their descriptions, the noncompliant horses showed more behavioral responses—moving around, resisting the clipper, kicking, etc.—than the compliant horses during the sham clipping phase and, to some extent, after clipping.
But the team found no significant differences in any of the physiologic stress measurements between the compliant and noncompliant groups. Horses in both groups experienced a rise in heart rate, salivary cortisol, and eye temperature during the sham clipping phase, said Hall. In other words, all the horses in this study appeared to find clipping stressful, but the compliant ones had simply learned not to react.
So does this mean that, in respect of equine welfare, we should stop clipping our horses? Not necessarily, Hall said. Sometimes as horse owners, we have to make the call to do things that our horse might not like because it’s still what’s best for him in the long run.
“We can’t explain (to horses) why having their coat clipped off may be good for their comfort and health,” she said. “But it’s sometimes not clear from their behavior whether they are finding it easy to cope with the things we do to them ‘for their own good.’”
But, Hall said, “if we are aware that they find it less than pleasant (even if they don’t show it), we can make sure we prepare them well and carry out procedures such as clipping in a calm and considerate way to minimize the stress experienced by the horse.”
The study, "An assessment of the aversive nature of an animal management procedure (clipping) using behavioral and physiological measures," was published in June in Physiology and Behavior.
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