I was thinking about this as Hal was warming my toes. Their internal temp is about 5 degrees higher than ours, somewhere around 102-103 degrees. My only guess is that it is like us running a constant fever. It is higher because it kills more germs in their bodies. Is there an alterior motive for this?
Thanks!
Sure I post in your threade, but it’s not like I’m following you or anything…
Think of your body temperature as being the result of your inner furnace. In a pot bellied stove (more appropriate in my own case 
) you put fuel in, it burns and the stove gets hot. If you put coal in instead of wood, it would burn hotter and the stove would be hotter. Let me remind the gentle reader that burning wood is a chemical reaction.
Now to your body. Your cells are performing gobs of chemical reactions, (conversion of ATP to ADP as an example) which are exothermic, meaning that they give off heat. As your body unleashes the chemical potential energy as heat, and your body loses heat (this is why you should wear a hat in winter), there tends to be a balance resulting in a body temperature around 98.6 F (37 C) - (orally).
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Since the original fuel for your body comes from the breakdown of food, this process of food conversion and energy “production” you may hear this referred to as metabolism.
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Now to the cat. Cats require more energy for some reason (to prepar to run from prey?). Therefore, they have a higher metabolism and have a higher balance of heat production to loss. This gives them a body temperature higher than ours.
As an added benefit, the higher body temperature probably helps to kill germs and what not - pure conjecture here.
[bonus info]
When you have an infection or some sort of outside yuckies in your body, your body tries to take care of it with chemical reactions. If this is systemic, you entire body temperature can rise and you get a fever. If it’s local, like a cut or splinter, the specific area might get hotter.
[/bonus info]
Here endeth the lesson.
How about because they’re covered in FUR???
There is a general relationship between basal metabolic rate (BMR), core body temp(CBT), and size. Smaller size predicts higher BMR and higher CBT.
Therefore your cat’s CBT (as well as your dog’s, and your bird’s) will be higher than yours. While the elephant that you keep asking your mom if you can keep in your room will have a lower CBT.
If they’re always running from prey, then where do they get the fuel to keep their temperatures so high?
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This brings up a new question: if a human has a fever of 103 or more, s/he will eventually suffer brain damage. How do cats and other small animals avoid this?
Short answer: they don’t. That’s why cats act the way they do.
Real answer: anyone?
thanks,
–sublight.
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Hah! Not my cat. He sleeps on my bed or on the porch all day, goes out for an hour or two at dusk to patrol his territory, and then goes back to bed for the rest of the night. Typical cat behavior.
What does he need extra energy for? REMs? Digesting Tender Vittles? Horking up hairballs on my comforter? Please!
Actually, a cat’s normal body temp is not that much higher than a human’s - 99-101.5 degrees F. I’ve seen those higher numbers given as normal many times, and I don’t know why, as I’ve taken hundreds of feline rectal temps and find 100 to be much closer to the average. At 103, my vet prescribes antibiotics! However, a stressed cat will shoot up to 102 like a rocket, and I suspect that is where those higher averages come from - it’s hard to check a cat’s rectal temp without stressing it! (It can be done, though.) FWIW, it’s also very hard to check a cat’s glucose level, as glucose does the same thing, and drawing blood is usually more stressful than taking a temp.
I’ve seen cats with a temp as high as 106 that didn’t appear to have suffered any brain damage, but that’s hard to determine. I don’t think I’ve ever seen a sick cat with that high of a temp - the ones I’ve seen were due to overheating.
I think some of the apparent difference (feeling like fuzzy little toe warmers) is due to skin temps. Your own core body temp might be 99, but the surface of your skin might be 97 or 98. (That’s why we have those lovely rectal thermometers, to obtain an accurate core temp.) As someone else pointed out, most cats are covered with fur, so while their core temp might be 100, their skin temp might be 101 underneath that insulation.
Burrow your 97 degree toes under the fur to that 101 degree skin, and you’ve got a 4 degree difference (and a nice little tootsie warmer).
Actually, they run at prey…not away from it (just a nitpick – point taken).
If you think about it they run very rarely. Something on the order of 18 hours a day is spent sleeping. The time they are awake they are pretty mellow. They maybe spend 5 minutes a day actually running.
Cat’s muscles are built differently from ours (humans). I’m not sure of the proper technical terms but their muscle density is much higher. The result? Excellent jumping and acceleration ability. The downside (there’s always a tradeoff)? They have practically no endurance. A cat can chase you down but if you manage to stay away from it for a few minutes it’ll have to give up the chase. Cheetas will actually overheat after only a minute or two of top speed running and must stop or risk killing themselves.
Catching prey is expensive in terms of energy for a cat. They can’t afford to fail very much so they conserve as much energy as possible when not actually hunting food. Their high metabolism ensures enough energy is available when it’s needed.