What is a common sign of dehydration in dogs?

The story behind the answer

Dry, tacky gums are a common sign of dehydration because mucous membranes lose moisture when a dog’s fluid levels drop. You may also notice slow capillary refill time (press a gum—healthy color should return within ~2 seconds), lethargy, sunken eyes, and reduced skin elasticity (a “skin tent” that doesn’t snap back quickly).

By contrast, excessive drooling often accompanies nausea or heat stress, frequent urination can indicate high fluid intake or urinary issues, and a wet, glossy nose isn’t a reliable hydration gauge. Remember: “Slick is good, sticky is sick.” If gums feel dry or tacky—or refill is slow—offer water and contact your vet, especially if symptoms persist.