Why is my dog so thirsty?

This link is a related post. https://www.rover.com/community/quest... If you can rule out normal thirst from panting, play, exercise, diarrhea, resource guarding, then it could be medically based and require attention. It could be quite serious. The vet can determine if possibility of: Diabetes, Kidney issue, Liver problems, Infection, etc.

Maintaining hydration is an important aspect of your dog's instinct to survive and stay healthy. Since water accounts for more than 60 percent of a dog's body weight, and because breathing, salivating, defecating, and urinating are all responsible for significant losses of water from a dog's body, it stands to reason that dogs need to take in a good amount of fluid each day from what they eat and drink Most average-sized dogs (around twenty-five pounds) will consume at least sixteen ounces of fluid in a day, either directly or as part of their food. Warmer weather and increased exercise, however, will put greater demands on them and require greater fluid intake. A little extra drinking and peeing is usually not much to be concerned about. If you are noticing steep increases in these two important functions, however, it is probably worth paying closer attention.