Some thoughts on what keeps dogs warm...

BradA1878

We are moving into our first winter with a full-time outside dog (Luytiy) and a few other dogs sleeping in our barn at night (Masha, sometimes a Shika or 2 - if they want to, and a few Akita).

Our dogs have always lived in our home with us, but we had to face the fact that our home is just not big enough for all the large breeds to sleep comfortably inside. Also, Luytiy's (and Masha's) job is to patrol the property 24/7, so he was always planned as an outside "working" dog (Masha barks too much at night right now).

*Luytiy has access to get inside the barn during the night too.

Never the less, it's still an adjustment for us to have some dogs sleep outside, and, even tho the barn stays comfortably warmer, now that it is cold out, Jen and I worry about them constantly (especially since at night it gets very cold). We have noticed tho, they are completely unaffected by the cold - Luytiy seems to love it, which is not surprising, but it is reassuring.

Then there is Blue, I was worried about him. As a pup he seem totally miserable in the cold, so I assumed that even as an adult he would be uncomfortable in the coldest months here - and would be inside more... But he seems to be totally fine out there in the AM cold (he is in at night).

This made me start thinking about what actually keeps dogs warm, and how cold is too cold for a dog...

Obviously, a dog's coat plays a huge role in keeping them warm, but in Blue's case he has very little coat - certainly not as much as our Nihonken. Blue doesn't even have a proper double coat (cow coat), his coat is very thin - like a sight hound or something.

So, what keeps Blue warm? Is it his extremely thick skin? His dark colored skin? His thick muscle mass?

I'm wondering now if skin thickness plays a bigger role in keeping a dog warm than coat length/thickness/type.

If we look at our dogs that enjoy being outside in winter the most: Ahi, Hilo, Luytiy, Masha, & Kahuna... They all have 2 things in common: thick, baggy, skin and a thick double coat.

Next in line are the ones that like to be out in the cold, but often ask to come in during the coldest times (or when they are inactive): Kona, Blue, Fuji, and Loa. They all have at least thick skin or a double coat, but not both (like the ones above do).

If you look at origin of our dogs, and think about the climate, the CO mos def comes from the coldest area (mountains of Russia, Georgia, Armenia) and they have the thickest, longest, and harshest coat of all our dogs as well as very thick (if not the thickest) skin (I have been told that their skin is as thick as a Neo or Bull Mastiff).

So, it seems that a dog's skin, much like a seal, may play as big of a role as their coat does in keeping them warm. I'm wondering if any of you have noticed this, or have any scientific data/background to lend to my thoughts?

For a dog like the CO, how cold it too cold?

How about for Blue, how cold is too cold for him? (he has very thick skin)

Can you think of a breed with a long coat that does poorly in cold weather?

We have been feeding the CO a higher calorie diet in preparation for winter - want to give them a little extra fat layer (but not too much) to help keep them warm. Luytiy looks amazing now (see pic below), and his coat is not 100% yet.

I'd love to hear your thoughts on this.

Ahi and Luytiy in their winter gear (thick coats)...





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sukoshi_mom

I think it's very important to give the dogs extra food during the winter so that they will have extra fat reserves to burn. I did this w/ my Dalmatians, Border Collie, and do it now with my Shiba.

Also, it's very important that the dogs have a dry, insulated area to be in. I would put individual dog houses or covered insulated areas in the barn that will allow them to conserve their own body heat, especially when they are sleeping.

I would also check to make sure that their paws are not extremely wet or packed with ice.

Put a thermometer in the barn to check temps. Decide at what temp threshold all the dogs come into the house.

Just some thoughts.

BradA1878

Yea, we have dog houses, wool blankets, sheep skins, and pine shavings in the barn, and Luytiy has has his "chill den" which was actually specifically designed to keep him warm in winter, and he can go into the barn to be warm with the Akita too.

So, I think we have the "keeping the dogs warm" thing covered...

I was asking more specifically about the "science" of what keeps dogs warm. Like what do they have (coats, skin, color) that keeps them warm and the "science" behind how it works.

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Calia

A comment I read somewhere went along the lines of if you can't feel the dogs body heat, then their coat must be working.

I do agree with your thick and baggy skin makes a better winter dog. Even though Tikaani doesn't look it, his skin is very loose and it's easy to get a good handful of it. Being a Sibe, his breed is known for cold survival and it is believed that they can handle and work in temps as low as 75 degrees Fahrenheit below 0. But then you have the breeds such as the standard poodle and the Afghan hound, who have tight skin and slender bodies, also meant to handle the cold.

But I wonder, if it also has to do with the actual body temperature of the individual breed. Different species have different body temperatures and different relations of mass to surface area. I'm not well versed in this, but I think it goes along the lines that big mass with small surface area has less heat loss than small mass with big surface area. A smaller animal must have a higher body temperature than a bigger animal since their body is losing more heat in a short amount of time. I have heard that smaller breeds of dogs have a higher body temp than bigger breeds, and in the same room the chihuahua is trying to gain warmth while the husky is trying to lose it.

Brad, is it possible for you to see a relation of this thought with your dogs? Aside for Blue (who is kind of the odd one out since he is the only one of your dogs with the single coat), does the level of each of your dogs temperature comfort (how much they like or hate the cold/warm weather) match with the size of the dog?

lindsayt

I don't have much, but I would think a good layer of body fat along with a good coat or heavy skin seems like more of a winning combination than thick or excess skin alone. Ike has really thick male skin and he loves being outside. He doesn't have a very good fat layer, though, so he just grows more coat to compensate. Of the cold weather adapted animals like seals, and whales who lack a coat, they have very thick skin and a super dense fat layer. Or, an animal can have a good coat and lots of body fat like the beaver and polar bears (who actually have a very dark pigment to their skin).

What about brown fat? I thought that more cold adapted animals kept this as adults, whereas mammals used to warmer conditions lost it. Like with sight hounds. Afghans have luxurious long coats but I see them all the time in jackets due to their lack of body fat and thin skin. Deerhounds and Wolfhounds who grew out of colder northern climes are distinguished in part from Greyhounds because of a longer coat but also their thicker skin.

Then there are people. We have thin skin in comparison to many other mammals, but most of us have more than enough body fat, and we have the ability to wear clothing to make up for our lack of coats. I thought I also learned somewhere that groups of Alaskan Natives tended not to lose their brown fat layer as they matured.

I'm guessing that a mammal can have 2 of 3 things (thick skin, adequate fat, thick coat) and survive very well in cold climate, but not do so well with only 1 of the 3 things. Blue has really thick skin, right? He doesn't seem ultra ribby from your pictures, so I'm guessing his darker coat color and the fat layer he has are enough help him retain heat. His ears might be affected in severe cold, but as long as he gets enough fat in his diet, the rest of him should be ok, right? Maybe a jacket for him in really bitter cold...

dlroberts

Just throwing this out there because I can't find a reference, but I have the strongest recollection that I hard somewhere metabolic processes affect cold tolerance as well. I know metabolic processes generate heat in the body, so it seems likely they could also have an affect on cold tolerance right?

WrylyBrindle

My brother's pointers have no fat and barely ANY coat, and he does put jackets on them for winter walks- BUT my point *ha!* is to say that thier metabolism is incredibly freakin high. These dogs eat huge amounts of food, compared to my dogs, and they throw heat like nobody's business. Their motors run at intense RPMs, and when you touch them they are very warm, and usually vibrating. They are ultra-generators but not good insulators, but they can keep up with the loss by their huge generating capacity. They have huge lungs and deep chests- they are all about combustion- fuel and O2.

That said, they are not left outside to relax in the snow. They are white and dont absorb solar heat that much. They are never still. They are bred to be able to run all day and hunt birds- and for these two specifically that means November along the Canadian border in the mountains.

I think high metabolism must beat fat, because I am always cold.

Calia

Animals with higher metabolisms are usually the smaller animals, such as rodents and birds. They are constantly losing body heat due to one reason or other, so thus must make more heat than a bigger slow metabolism animal. It kind of relates to the whole mass thing I mentioned earlier. If an animal can't hold the heat in (wither with fat, fur or size) than their body must work to keep warm, and the animal must eat more to keep the furnace burning.

BradA1878

This is interesting!

@Beth - The size thing is interesting, I discussed this once with a friend, about how during the ice age animals were much larger than they are now - perhaps the connection can still be seen in mammals that live in colder climates now. Certainly, if you look at our dogs, the larger ones are the ones that seem to not mind - or even enjoy - the cold. Also the same logic applies within each breed group here, for example, Ahi seems to like the cold more than Loa and Luytiy more than Masha, and Hilo & Kahuna more than Fuji and Lani.

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@Lindsay - I had never heard of the "brown fat" before, I had to look it up. lol. Can you think of an animal that has all three things? Fur seal, perhaps?

Yes, Blue has very thick skin - not as thick as a Neo, but certainly thicker than average. I've considered getting him a coat, I just don't want to spend the money as I know he has another 2 years of growth to go... But, I may just have to do it, especially if we want him to snowshoe with us this winter. You mention Blue's ears, I spend a strange amount of time worrying about his poor ears. I worry they will get too cold, so I always limit his time outside in the very cold times... then I worry about the dogs, they all pull on them. Poor Blue. Sometimes I think we did him a disservice by not cropping them, then he would have not had an issue in cold or w/ the dogs playing. :oT

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@Dave - That's another great point, and another reason I think Blue does so well in the cold - he has a sick metabolism. He eats 10 cups of food a day! 10 cups! And he still looks thin! But, Blue also has a lot of mass, so perhaps a high metabolism + thick skin + a lot of mass = warmth?

Then there is Maui, he has a very high metabolism too, but cannot coupe with temps under 30F or so. His creamy coat is just too thin. I guess it goes back to Lindsay's 3 key attributes... or should it be 4, should we include metabolism?

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@Chrystal - I think a lot of keeping warm has to do with moving a lot for dogs. Blue never just lays out in the snow, he is always moving, while Luytiy, Masha, Huna, and Hilo spend a lot of time laying in the snow (in the shade too!).

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Calia

Here's an interesting fact (or something) about Siberian huskies and metabolism. It is thought that the reason why Sibes have such great endurance when it comes to racing/mushing is that they are capable of reducing their metabolism. With a reduced metabolism, they are burning less fat and energy and capable of just going and going and going. I think the fact that they are creating so much heat from the friction and movement, their bodies do not need to actually make heat.

dlroberts

I read somewhere that sled racers in part select their alaskan huskies based on their coats. They will have a dog they want to purchase sleep outside on the snow. If in the morning the snow is melted where the dog slept, they know their coat does not insulate enough and will not purchase the dog.

So, perhaps fat, coat, and skin all contribute to trapping heat (rather than keeping cold out) and metabolic processes generate it? So really it's two categories: insulation and generation. A dog that's weak in both categories will have very low cold tolerance. A dog that's high in both (like alaskan huskies) will have really high cold tolerance. Dogs that are strong in one but weak in the other will have moderate cold tolerance. That's probably an oversimplification (as in there's probably more than just 3 gradations), but it seems to fit with the mental model I'm forming.

dlroberts

Errr. Forgot mass. I think mass, like Beth said, contributes to storing heat. So that would probably fit in the insulation category. Perhaps insulation isn't the right word then. Perhaps retention is better. Yeah, so two categories: retention and generation. Does that make sense?

Leonberger

Mass (or more accurately sheer size) helps keep animals warm, since a large animal has a smaller relative surface area than a small one. A relatively shorter muzzle will also help reduce heat loss, since there will be less surface area exposed to interchange heat with the environment.

I would go with insulation, Dave. Insulation helps retention by limiting the heat exchange with the environment.

BradA1878

I agree, I like Insulation & Generation. This is interesting guys, thanx for your input.

Am I the only one with an outside dog?

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sunyata

I am going to go back to what Beth said about body temperature...

From my own personal experience, I know that body temperature has a lot to do with cold/heat tolerance. Due to some strange medical issues, my average body temperature is about 3 degrees less than most everyone else's. (95.4 F) If I am in a room with someone of similar body structure (weight, height, etc.), I always feel colder than the other person and will either reach for the thermostat to crank up the heat or for a nice thick sweater (even during the summer!).

So, I wonder... If Big L tolerates the cold better than Masha, is there a difference in their average body temperatures. Same goes for Ahi and Loa, etc.

Just a thought.

dlroberts

LOL. My average body temperature is relatively low too (97.2 F), and I'm ALWAYS hot. So there goes that theory :-/

BradA1878

Haha, strange, my average temp is always high: 99.9. I used to use it as way to get sent home when I was in grade school. )

Oh, and, I am ALWAYS cold! LOL

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Calia

LOL, I like this discussion:)

Sometimes, body temperature means nothing if blood circulation is poor. I have a normal body temp, but due to poor circulation I am easily chilled and can get stiff joints when the temp goes under 75F (my toes/fingers will literally turn blue).

Rui said. "A relatively shorter muzzle will also help reduce heat loss"

I would have to disagree to some extent because the muzzle helps keep the body from getting chilled when inhaling. With each inhale, the muzzle takes the brunt of the cold, warming the air to keep the inside of the chest from losing too much heat. The muzzle also helps cool the dog in summer.

Flat faced dogs are an example of how lack of muzzle can lead to poor ability to handle beyond room temp. My mother's shih tzu can't last more than a 10 minute walk before he collapses from over heating in summer or shivers uncontrollably in winter. He is a stocky, wrinkly dog but really wouldn't be able to survive a night outside in winter or summer.

Leonberger

That's why I said "relatively". It's not the shorter the muzzle, the less heat they lose, but there's a balance, an optimal point if you will.

If you compare desert foxes to snow foxes, snow foxes have a relatively shorter muzzle (if you ratio length to width) to keep the exposed area smaller. It's true that air going in gets warmed up in the nose, but if more area is exposed to the air, more heat gets changed with the surroundings.

Flat faced dogs are a mess when it gets to heat loss, they suffer terribly in hot weather, but they seem to be less troubled in the cold (although still not well). At least that's what I see around here.

tsukitsune

Friends of mine that live in Utah do snow camping (ski, make snow tents, etc) with their two dogs. The say metabolism is the greatest aid for a dog, coat second, and sharing the bivy sack third. They have a cattle dog mix and a sheepdog mix, and I believe the sheepdog mix is the higher metabolizer, carrying their water & food and sleeps on top of the bivy, not in it - while the cattle dog is slower on the trail has to sleep in the bivys with them.