It can be pretty frustrating when our dogs shake water all over us after coming in from the rain, but have you considered how quickly a dog dries him/herself off? When we are soaked, we need a large towel to dry ourselves off and anywhere from fifteen to sixty seconds to do it. Typically, a dog will achieve a feeling of dryness in under ten seconds — usually around four or five.
As it turns out, most quadrupedal mammals are extremely good at drying themselves off in a way bipedal mammals are not. That is to say, a dog is economical and efficient in their task of drying off. In fact, scientists and engineers are developing clothes dryers, washers, and other apparatuses that mimic the science behind how four-legged furry animals shake the water from their bodies.
It goes like this. A dog will plant their paws to the ground and their general core stays stationary for the duration of the drying. The shaking off involves rapidly moving their loose skin — at much the same speed as a whip crack — and having the fur and skin move back and forth around the center of their body. This “whip crack” expels water from all angles and any water nestled into the fur is either absorbed into the skin or brought to the surface of the dog coat.
The key to this trick is this skin. A dog’s skin is much looser than a human’s and actually — when shaken rapidly — ripples around their frame and muscle. Picture a dancer who while spinning around is wrapped around in her skirt, dress, or top. The way our clothes respond to our rapid movements is similar to how a dog’s skin responds to theirs.
And there’s variant speeds at which a dog must dry off. For instance, many breeds of smaller dogs take more energy to dry off than a larger breed. For example, a Yorkie or small terrier will need to expel more force (around 20 g’s) than a Labrador or Samoyed (under 4 hertz) because their core radius is smaller and closer to their fur and skin. It’s a bit like being on a merry-go-round. If you choose a horse closer to the center of the circle, you will experience less force or pull — a relatively smooth ride. If you choose a horse on the outer edge and circumference, you will feel the drag and pull much more and are more likely to notice the speed of the carousel. So, a smaller dog can only shake off so much moisture if they shake at the same rate of a dog that’s more than twice their size, hence their need to shake more rapidly.
To see a dog drying off in slow motion, here’s a video which was produced by the BBC.
Even though dogs are extremely good at drying off, it may be a good idea to keep a towel at hand — and an umbrella to prevent further wetness.