Your dog keeps their nose wet in three different ways:
- Mucus: Glands in their nose produce a fluid that helps cool them down
- Licking: They use their tongue to keep their nose clean and moist
- Environment: They pick up moisture when putting their face into wet or damp environments
If this seems like an awful lot of effort to keep their nose wet, you’re not wrong. Moisture is crucial for enhancing your dog’s sense of smell, without which they navigate the world virtually blind.
How wet noses improve a dog’s sense of smell
Although small and humble-looking, your dog’s nose is a powerful scent-smelling apparatus, containing up to 300 million scent receptors. For context, humans average only 6 million.
The act of sniffing, whether on the ground or in the air, physically sends scent particles into the nasal cavities where they get trapped in the aforementioned mucus. From there, the scents are carried to the Jacobson’s organ located in the roof of the mouth. Also known as the vomeronasal organ, the Jacobson’s organ is designed specifically for semiochemical communication–aka pheromones.
Your dog helps this process along by keeping their nose wet, instinctively licking it throughout the day. Every dog breed, regardless of size or shape, has been observed doing this. The drier the nose, the harder it is to smell!
An average-sized dog produces about a pint of mucus per day, though they thoughtfully keep it out of sight by allowing it to flow down their throat. Due to facial anatomy, some breeds have the mucus slide down their inner cheeks and out their mouths, forming long strings of drools. If you’ve ever noticed a correlation between dog breeds known for the sensitivity of their noses and the ones known for the amount of drool they produce, congratulations–you’re completely correct!
The exception is brachycephalic or flat-faced dogs, who cannot clear the mucus out as quickly. The accumulated fluid blocks the incoming scent molecules, resulting in pups who score lower on scent discrimination but drool just as much as their bloodhound brothers.
Reasons why your dog's nose is dry
A healthy dog typically has a cool, wet nose, but the occasional dry nose is not abnormal. If your dog has been napping for a while, the cause of a dry nose is self-explanatory–they haven’t been awake to moisten it. Dehydration can also cause their nose to dry out and resolves itself after some water and rest.
Just like human skin, your dog’s nose can get sunburned or wind-chapped after being outside for long periods of time. If your dog likes to snooze next to a heating vent or a fireplace, the ambient heat dries it out as well.
Your dog’s nose gets drier as they age. Sense of smell declines as dogs age, though little is understood about why.
Finally, a hot, dry nose can indicate fever or allergies. Other symptoms such as mucus-y eyes, nose crusting, and discolored gums accompany illness. In these cases, a veterinarian can help determine the underlying cause.