How many times have you gotten wet with your dog’s after-bath shake? Probably every time after your pooch has had a shower or a swim. Isn’t it? Dogs tend to shake their body to remove the extra water on their coats. You may not believe, but a wet dog can shake off 70% of the water on his coat in just 4 seconds. This effective way of dealing with water is not random; there is science involved that may explain the mechanics of a wed dog shake.
This mechanism of pets shaking off the water is led by none other than the process of evolution. This process of natural selection made subtle changes over time to increase the survival instinct in mammals and other creatures. During this process, furry animals evolved and used shaking their bodies to dry the coat. This survival technique is not limited to dogs, tiny rats or large predators like bears equally use this process to shake off water from their body.
It helps the furry animals to resist hypothermia after a bath or swim. A wet coat becomes deprived of the ability to seize warm air around the dog’s skin. Shaking off water from the coat has two benefits: it saves the canine from hypothermia and the second is that it is calorie-effective option. If a furry animal weighing around 60 pounds opt for evaporation by sun instead of shaking his body, then 20% of his calorific intake may be required to dry the body. Thus, this is not a practical option, especially in lower temperatures.
How can dogs shake off 70% of water in just some seconds?
The reason why furry mammals including canines are able to shake off maximum water in mere seconds is due to their loose skin. They start with a head twist and send an energy wave to the entire body. In this way, every part of the body moves with the help of their loose skin. Although every part of the body and skin moves, the body cannot rotate as far as the skin can due to its floppiness. As soon as the dog starts shaking his head, acceleration is increased making the body and skin move throwing off the water. This is also helpful in regulating the body heat.
How fast does a dog need to shake to remove the water?
The researchers at the Georgia Institute of Technology used high-speed cameras to find answers to this question. They captured wet furry mammals shaking at the Atlanta zoo, in a park and in the lab to understand the mechanism and the speed of shaking off the water. The researchers noticed that a large or medium dog shakes 4-5 times a second and throw off almost 70% of water. Whereas smaller dogs and cats can remove water from their coat and body in almost 6 shakes in a second.
How is the wet dog shake related to its size?
The researchers found that the speed of the shake is relative to the size of the canine. When a wet canine starts shaking his body, he generates a force that is 10-70 times greater than the gravitational force. This force is high enough to damage the dog’s eyes by the velocity of centripetal force. Thus, the mechanism of a wet dog shake is a combination of centripetal force that moves the body in a circle and creates surface tension. Larger the body, lesser the rotations needed to generate the force required to shake off the water.
This is the plain science behind a wet dog shake which is quite interesting. Humans cannot shake off the water after bath because our skin is taut and because of it, we cannot generate the force needed to shake off the water. Luckily, we evolved in experiments and made towels which are ultimately used to wipe off the water sprayed by our dog’s shake!