By Kip Tulin MD
Did you ever see a dog shake water off of his fur after getting wet? How about a horse shaking the dust off after a good roll? I have watched Freedom Farm's horses do so in the arena and wondered, how well does it work?
My curiosity led me to an article by David Hu and Andrew Dickerson from the Georgia Tech Department of Mechanical Engineering and Biology.
It seems that all furry mammals have a finely developed shaking mechanism to clear water (and dust) from their fur. This ability is critical to the survival of an animal, since having wet fur and skin can use up a lot of precious calories just to keep warm. Dr. Hu's research showed that rhythmic shaking of the fur and the loose underlying skin can expel up to 70% of the accumulated water. Also, the smaller the animal, the faster the shake. A mouse can oscillate at an amazing 30x/second while a bear clocks in at 4x/second.
Here's a short video I shot of our very own Snickers having a good roll and shaking off the dust. In the slow motion portion you can see how highly coordinated her movements are. Oh, and turn up your speakers!
A final note to humans....our tight skin makes our shaking rather inefficient. Stick with using a towel to dry off.
(Originally published November 2014)
