Dogs normally have wet noses, and it is their tears that help keep their noses wet. A small passageway, the nasolacrimal duct, runs from the eyes to the nose. Tears from the tear gland maintain a tear film on the eyes at all times for lubrication and protection of the eyes. Some of these tears drain down to the nose via the nasolacrimal gland, which keeps the dog’s nose moist. A moist nose can also help enhance a dog’s ability to smell.
Although it is not always true that a dry nose is an indication of illness in dogs, studies have shown that tear production can be affected (decreases) when a dog has a fever, eye problem, or is dehydrated.
Also, the anatomy of some canine breeds may prevent proper functioning of their nasolacrimal gland. Pugs, Shih Tzus, and other brachycephalic canine breeds experience excessive tearing of the eyes. You can click Veterinary Clinic Profit to know more details.