Every dog reacts differently to snow and colder temperatures. Avalanche rescue dogs work in snow-covered terrain and thrive in it. Paws have no fur to keep warm in freezing weather.
Think of snow and you probably think of all that snow and ice bothering your dog’s paws, however new research actually explains how dogs keep themselves warm on frozen ground. All that snow and ice does not seem to bother our furry canine’s paws and here’s why.
Most dogs love to play in the snow. The smell of snow fills the air as our furry companions dig it up, sniff it and roll around in it. You might wonder how dogs are able to bear colder temperatures and snow on their paws. Original research done in 1930 found that wolves and sled dogs did not suffer from frostbite and that their metabolism adjusted to colder conditions. Frostbite only occurred if the dog had an injury.
Research from the Yamazaki Gakuen University in Tokyo, Japan, found that our furry friends have a specialised circulation system in their paws that prevented their paws from freezing up in the snow and kept their paws warm on icy ground. This system allowed them to regulate their body temperature on cold snowy terrain. Researchers compared domestic dogs’ circulation systems to that of penguins and polar foxes and found that their circulation systems have many things in common. This latest research also revealed the following interesting facts.
Using electron microscopes to map out the internal structure of dogs’ paws, Dr Hiroyshi Ninomiya found that heat was transferred from the artery to the network of veins and that cooled blood could not return back to the body. This same system occurs in penguins’ beaks as well as dolphins’ fins. Studies have shown that dogs can keep the tissue in their feet from freezing because they have a large amount of freeze-resistant connective tissue and fat in the pads of their paws. The close proximity of the arteries to the veins in the footpad means that heat is conducted from one blood vessel to another. Arteries carry warm blood directly from the heart and then feed the thinner veins to the dogs’ extremities. The warm blood that actually passes by the cool blood warms up the cooled blood in the paw that was in contact with the icy ground. This prevented the dog’s body from cooling down and kept the dogs paws at a constant temperature. This in turn helps to speed up warming in your dogs’ paws.
Researchers compared the circulation system in our furry best friends to that of the polar fox, which hunts on ice and exposes it’s paws to snow and ice frequently. The reason behind the polar fox not freezing their paws at below freezing temperatures is that they are able to regulate their body temperatures in freezing harsh climates.
Dr Hiroyshi Ninomiya and his team concluded that dogs were like penguins in the Antarctic, since penguins have a counter current heat exchange system in their wings and legs, so that heat would not dissipate and they could keep their bodies warm at all times. He compared dogs to penguins using the counter-current heat exchange system in the dogs’ paws and comparing it to the penguins’ beaks. Inside of a dogs paw, the veins and arteries are unusually close together, and heat is shared. The findings are published in the journal Veterinary Dermatology.
Researchers are excited at the latest findings since they believed that it was not a necessary adaptation for a domestic species such as a dog to have such a specialisation. Many believe that these new findings have evolutionary causes, meaning that ancestors of the domestic dog lived in much colder, snowy climates in order for such an adaptation to have come about in the first place. So next time you’re out playing in the snow, why not let Fido hang out with the penguins and polar foxes?
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