While it’s normal for dogs to take water breaks throughout the day, you may be a bit concerned if you notice your pet drinking excessively.
Can a dog drink too much water? And, could it be a sign of something larger? “An owner should be concerned if their dog drinks the entire bowl at once and continues to drink every time water is offered,” shares Dr. Elizabeth Appleman, staff veterinarian at NYC’s Animal Medical Center. Further, if you find yourself constantly refilling the water bowl, if your dog suddenly starts drinking water from the toilet, or if you happen to notice that your dog is urinating more than normal, it could be a sign of a potential disease or condition. It’s a good idea to get a feel for how much your dog typically drinks when he’s healthy. If you notice a significant change, alarm bells should go off.

Why Does My Dog Drink So Much Water?

Drinking more water is medically referred to as polydipsia, and it is one of the most common problems seen in veterinary medicine, according to Appleman. Polydipsia has a wide range of underlying causes, “Certainly dogs can become polydipsic during warm weather, particularly right at the start of the change of seasons and before they have time to adjust to the hotter temperature,” says Appleman. Dogs will also drink more if their bodies are losing water through watery diarrhea, excessive panting or blood loss. “This represents the body’s attempt to rehydrate and restore normal blood volume,” she says.
Can Excessive Water Drinking Be a Sign of an Underlying Disease?

If your dog is drinking more than usual—some dogs even drink so much and so quickly, that they will regurgitate it right back up—it could be a sign of a medical issue. “It can be a long diagnostic process to figure out why a dog is drinking and urinating larger volumes, and sometimes it is difficult to ultimately find an answer,” says Appleman.

Polydipsia, along with increased volume of urination (polyuria), can be caused by the following, amongst other things:

Kidney insufficiency
Diabetes mellitus
Diabetes insipidus
Adrenal hormone disease (such as excess cortisol production, called Cushing’s disease; or cortisol deficiency, called Addison’s disease)
Liver disease
Infection
Abnormal electrolytes (high calcium, low potassium)
Treatment with certain drugs (corticosteroids, diuretics, etc.)
Psychogenic polydipsia

Is it Ever Normal for My Dog to Drink Excessively?

While excessive water drinking that is out of character for your dog may signal an issue, some dogs may simply drink a lot of water. “Some dogs are naturally excessive water drinkers,” says Appleman.
“These tend to be large-breed, playful dogs that like to amuse themselves by drinking water, or are very active and need to replenish water loss from panting.” The most important aspect in deciding if there is a problem is identifying a change in baseline of water consumption. Try to be aware of how much your dog drinks on a regular basis, take note and consult your vet if the amount suddenly increases or decreases.
What Should I Do If My Dog is Drinking Too Much?

While most of the diseases that correlate with excessive water drinking have successful treatment options, “The difficulty is determining the correct diagnosis,” says Appleman. “Once the diagnosis is made, your veterinarian can almost always reduce (though maybe not fully resolve) water consumption and ameliorate the constant thirst and urination the dog is experiencing.” Many of the conditions that can cause dogs to drink a lot of water are quite serious. If you have any concerns about your dog’s water consumption, make an appointment with your veterinarian as quickly as possible.