Why Are Dogs Noses Wet?



Ebby's Nose

This is a question that I actually wondered myself and thought I would research a little and share my knowledge.  I know it hard to believe that as a veterinarian I wouldn't know this....  But contrary to popular belief I don't really know 'everything'...  Don't tell my boyfriend I like to keep him thinking I'm a genius! 

In my research online I found a wide range of thoughts, some very simple and some that seemed a little more scientific.  So the next thing I did was to consult my veterinary textbooks.  Much to my dismay they never had a clear cut/slam dunk answer either.  Soooo, I decided I would share with you what I found online and in my textbooks and end with my own thoughts on the real reason why.

This was an answer written in USA Today as to why noses are always cold:

-We've sure felt them — cold and wet pressed against us — but dogs' noses are not always cold, even when they're well. A dog's nose changes through the day: wet and cool one moment and warmer and drier the next. The nose wetness (or lack thereof) also changes with the humidity. The nose norm varies from dog to dog.

-A dog's nose, though, tends to be cool and moist just as the inside of a human's nose.

-A dog has special glands inside his nose that secrete a watery fluid to keep the inside of the nose moist and to help cool the dog through evaporation," says Holly R. Frisby, veterinarian at Drs. Foster & Smith, Inc. This moisture can extend to the outside of the nose, making it shiny, wet, and cold.

-Also, they continually lick their noses.

Here's one from Wiki Answers:

Dogs noses secrete a small amount of mucus which serves two purposes: to help their sense of smell, and to keep themselves cool. The thin layer of mucus helps with the absorption of scent chemicals from the air. In addition, the nose, along with the mouth and the pads of the feet, is one of the locations where dogs bodies release heat.
A dry nose CAN mean the dog is sick, but a perfectly healthy dog may have a dry nose, as well.

Dr. Mason's Veterinary Textbooks:

The nose or 'nasal plate' is kept moist in cattle, pigs, and dogs.  Other species don't have a constantly moist nose!!!  Hmmm, that taught me something..  In dogs this is kept moist from an overflow of secretions, from glands in the nasal sinus (space between the outer nose and the airway).  These gland secretions may have a social significance, hence the nose-to-nose sniffing dogs do when they meet. (-CRAZY-, the things you learn).  These secretions have an important function; they humidify and help cleanse the air before it gets to the lungs. 

I also learned that the nose is actually bare skin!  I had to go look at my dogs nose!  It doesn't look like skin to me!!  The surface of the nose (skin!) is irregularly divided, creating a pattern believed to be individual and therefore available as a means of identification (nose printing).  Book-em Danno!

My Conclusion:

I think the dog's nose being wet is just a side effect of normal nose secretions.  I'm not convinced it was actually designed to be wet, it just happens.  Our noses are always moist on the inside, but the dog just wears its nose on the outside!  I think it’s normal for there is going to be a wide variance of 'moistness', just like in people.  If you see a sudden change either way (runny or dry), I recommend consulting your veterinarian for a physical exam.

I hope this answered everyone's burning questions about 'Wet Noses".  I know that I can sleep a lot better knowing that little wet nose touching me is just a little nose juice!