You're used to your dog's cool wet nose in your hand, looking for affection. But this time when he nudges you, you notice your dog's nose is dry and warm to the touch. Does that mean he's sick?

Not at all. A dog's nose naturally changes from wet and cool to warm and dry several times over the course of a day. Most times, a dry dog nose is a completely normal physical phenomenon. But should you ever be concerned?

Why Is a Dog Nose Wet, Anyway?

There are two reasons a dog's nose is naturally moist:

• A thin layer of mucus on a dog's nose helps him smell. That superior sense of smell is partly due to that moist layer, which helps absorb and hold scents. You might even see your dog licking his nose — a way to actually "taste" the smell, giving him even more information about what it is, says Vetstreet.
• A dog's nose is also one of the few places dogs can use to cool down. Dogs don't have sweat glands like their human owners. Instead, dogs "sweat" from their noses and the pads of their feet.

Dog Nose is Dry: Should I Be Concerned?

Most often, a dog's dry nose is nothing to be concerned about. Some dogs naturally have drier noses than others, for one thing. A dry nose could simply indicate a dog just woke from a nap in the sun or near a heater or that your four-legged friend needs a drink of water from slight dehydration.

But sometimes a dog's dry nose can be a side effect of a medical issue, such as:

• A sunburn. If your dog has a dry, red nose or the nasal skin is flaking, a sunburn might be to blame. Talk to your veterinarian about special lotion for protecting your dog from the sun. Dogs with pale or pink noses are especially susceptible to sunburn. Protecting their sensitive snouts is important because repeated sunburn can lead to skin cancer, says the United States Dog Agility Association.
• A skin disorder. If your dog's nose is cracked, has scabs or sores, he might be suffering from a skin disorder. Your vet can let you know if that's the problem.
• Severe dehydration. A dry nose will likely be just one of many symptoms in a dog suffering from severe dehydration. Other symptoms include sunken eyes, dry gums, loss of skin elasticity and weakness. Immediately direct him toward water and seek medical attention for a dog you believe is suffering from severe dehydration.
• Odd Colored Mucus: When examining your dog's nose, look for any nasal discharge. If your dog's nose runs, the mucus should be clear. If your dog's nose has bubbly, thick, yellow, green or even black mucus, see your veterinarian.