Why Is My Dog Drinking So Much Water? Causes & Concerns
Published by MaunaPet. Editorial policy and sources.
It's normal for a dog to drink more water after a long hike or on a hot summer day. However, if you notice a sudden, unexplainable increase in your dog's thirst that persists for days, it could be a sign of a serious underlying medical condition. This excessive thirst is medically known as polydipsia, and it usually goes hand-in-hand with excessive urination (polyuria).
What is Normal Water Intake?
On average, a healthy dog should drink about 1 to 2 ounces of water per pound of body weight per day (roughly 50-60 ml per kilogram). Dogs eating dry kibble will naturally drink more water than dogs eating canned or wet food, which has a high moisture content.
Common Causes of Excessive Thirst (Polydipsia)
If your dog is drinking significantly more than the normal amount, the following medical conditions could be the cause:
- Diabetes Mellitus: Just like in humans, high blood sugar levels cause excess glucose to spill into the urine, taking water with it. The dog drinks more to compensate for the fluid loss.
- Kidney Disease: When the kidneys lose their ability to concentrate urine, the body loses excess water. The dog must drink constantly to prevent severe dehydration.
- Cushing's Disease (Hyperadrenocorticism): An overproduction of cortisol by the adrenal glands often causes a dramatic increase in both thirst and appetite.
- Pyometra: A life-threatening infection of the uterus in unspayed female dogs. Toxins released by the bacteria can affect the kidneys' ability to concentrate urine.
- Liver Disease: Can affect the body's fluid balance and metabolic processes, leading to increased thirst.
- Hypercalcemia: Abnormally high calcium levels in the blood, which can be linked to certain cancers or parathyroid issues.
- Medications: Drugs like corticosteroids (Prednisone) or anti-seizure medications (Phenobarbital) routinely cause increased thirst as a side effect.
How to Measure Water Intake
If you suspect your dog is drinking too much, measure it! Fill their bowl with a known quantity of water (e.g., 4 cups) in the morning. After 24 hours, measure what is left. Do this for a few days to get an average, keeping in mind that evaporation or multiple pets using the bowl can affect the results.
Diagnostic Workup: What to Expect at the Vet
When you bring your dog in for excessive thirst, the veterinarian will typically start with:
- A complete physical exam.
- Blood Work (CBC and Chemistry Panel): To check kidney and liver values, blood sugar, and calcium levels.
- Urinalysis: To check the urine concentration (specific gravity), look for glucose (sugar), protein, and signs of infection.