What is With That Wet Dog Smell?

wet-dog-smellYes, we know. Your dog is the cutest, best dog in the world. But let’s get one fact straight. Your dog stinks when he’s wet. As in stinks-like-the-inside-of-an-old-shoe-covered-in-poo-stinks. Assuming that you do not suffer from anosmia (the fancy word for the inability to  smell), you simply cannot refute that there is a distinct wet dog smell and your dog has it, too. But why the odor? The Weasel was curious, too.

Why Smelly Things Smell

If a tree falls in the forest and no one around is there to hear it, does it make a sound? Though perhaps less philosophical, a similar question can be asked of smell. Does smell inherently exist without the ability to smell? It can be argued that smelly objects only have a smell because we have the olfactory systems to detect it.

While this question is one to ponder,  what we do know is that smell is caused by the detection of chemical compounds in the air. Those compounds stimulate the receptors of our olfactory system sending electrical impulses to the brain. The brain, the powerful organ that it is,  then interprets those signals, which are analyzed, stored, and matched with other known odors, past experiences, and memories. This explains why you know that wet dog smell and can even compare it to other smells. As in, “you smell like a wet dog.” Don’t use this as a pick-up line.

So in order for something to have a scent, smelly molecules must be small and volatile enough to make their way through the air to your nose. Simply put, they must be easily evaporated and concentrated enough in the air for you to get a whiff.

The Wet Dog Smell

Like anything smelly, your wet dog lets off odorous molecules into the air. Those molecules are organic acids produced by bacteria,  which are present on your dog’s skin. Like many mammals, dogs produce an oily substance called sebum from sebaceous glands in the hair follicles. Humans produce sebum, too. While sebum is generally healthy for skin and hair, it can build up and will eventually mix with bacteria on the skin, which can make for some funky smells.

So why doesn’t your dog stink like wet dog all the time? Well when a dog gets wet, those organic acids produced by bacteria are dissolved in the water on the fur or hair of the wet dog. As the water evaporates, the concentration of those smelly acids increases, meaning that they will evaporate more and increase the number of molecules in the air for our noses to detect.  The water and its evaporation effectively amplifies the aroma, which explains why your cute, cuddly dry dog doesn’t stink like wet dog.

Think about it this way, wet dog smell is to a dog what body odor is to people, but dogs don’t wear deodorant.

Does your dog smell worse than wet dog, even when dry? Visit your vet. This could be a sign that something is wrong.

Sebum is a funny word. Learn more about it here.


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.