12 Potential Causes of Excessive Thirst in Dogs

Updated August 3, 2021
Golden Retriever drinking water outdoors

Your dog should intuitively drink the right amount of water for their individual needs. However, if their organs or systems aren't functioning correctly, they may feel compelled to drink larger volumes. If you notice your pet making more frequent trips to the water dish, or you're filling the bowl more often than usual, these signs could indicate a medical problem. It's important to understand the causes of excessive thirst in dogs so you can better identify when it might be a cause for concern.

What Causes Excessive Thirst in Dogs?

Increased water intake, described as polydipsia, could result from several conditions.


Canine Diabetes is a fairly common disease that affects approximately 1 in every 300 dogs. The disease involves an inability to control the amount of sugar, or glucose, in the blood. These high levels of sugar cause dogs to produce more urine, resulting in increased thirst to compensate for the loss. Other signs of diabetes include increased volumes of urine, increased hunger, and weight loss. With the appropriate management, typically involving insulin injections and diet change, diabetic dogs can lead full and happy lives.

Urinary Tract Infection

If your dog has a urinary tract infection (UTI), they may drink increased volumes of water. Bacteria typically cause UTIs, which affect about 14 percent of dogs at some point in their lives. In addition to excessive thirst, other symptoms that could point to a UTI include frequent urination, straining to urinate, bloody urine, urinating in the house, or excessive licking of genitals.

Kidney Disease

Kidney disease, also referred to as renal disease, is often associated with excessive drinking of water. Dogs with failing or damaged kidneys cannot concentrate their urine; therefore, they urinate large amounts of dilute urine and drink large volumes of water. Many dogs in kidney failure also exhibit a decreased appetite, vomiting, and weight loss. Depending on the cause of the kidney disease -- whether it results from chronic damage or acute injury from a toxin -- and the progression of the disease, prognosis and treatment options vary.

Cushing's Disease

Cushing's disease, or hyperadrenocorticism, involves an overproduction of cortisol from the body's adrenal glands. Typical symptoms of Cushing's disease include excessive drinking and urinating. You may also notice your dog eating more than usual, and they often develop a "potbellied" appearance. Treatment for Cushing's involves long-term oral medication.


Hypercalcemia occurs when a dog has too much calcium in their blood. This could result from various conditions, including abnormal parathyroid gland function, kidney disease, Cushing's disease, bone disease, and cancer. Excessive drinking and urinating are two of the telltale signs a dog has become hypercalcemic, as well as poor appetite, lethargy, vomiting, or general weakness.

Dog lying on sofa at home, looking ill and sad


Hypoproteinemia is a condition where a dog possesses unusually low levels of protein in their blood. This protein loss is typically the result of illnesses such as heart disease, lymphatic disorders, parasitic infections, cancer, ulcers, or gastrointestinal disease. Dogs with hypoproteinemia generally drink high volumes of water. Treatment varies based on the underlying disease and severity.

Liver Disease

One of the symptoms of liver disease is increased thirst. This is related to the impairment in the liver's function, including waste removal in the body. Accompanying symptoms include lethargy, poor appetite, weight loss, swollen abdomen, vomiting, diarrhea, and jaundice. Liver disease may be treatable in some cases; however, dogs with severe liver disease may not have a good prognosis.


Female dogs who have not been spayed are at risk of developing a pyometra, an infection of the uterus, often spurred by hormonal fluctuations. Significant infections like pyometra can motivate dogs to drink water excessively. The preferred treatment method is the surgical removal of the infected uterus.


Another bacterial infection that can cause excessive thirst is leptospirosis. Dogs contract this infectious disease by coming into contact with the urine of an infected animal -- typically wildlife or another dog. Leptospirosis is zoonotic, meaning you could get this disease from your dog if they have it. Although lepto can be treated, it may result in permanent organ damage.


Certain medications can lead to excessive thirst in dogs. Corticosteroids like prednisone, diuretics such as furosemide, or phenobarbital, a medication used to control seizures, have been known to make dogs drink water excessively. Although this may be a common side effect with some drugs, it's always best to report any changes coinciding with new medications to your veterinarian.


If your dog is dehydrated, they'll likely drink more water than usual. Dehydration could be caused by overexertion or warmer weather due to fluid loss through panting. So, if your dog played more vigorously than usual or the temperature has soared, it's not uncommon to see them drinking more water.

However, dogs may also become dehydrated because of fluid loss from vomiting, diarrhea, or a fever. If your dog is drinking more to compensate for this type of moisture loss, it's important to seek veterinary care.

Psychogenic Polydipsia

Healthy dogs may drink increased amounts of water for no plausible reason. They may do so out of boredom, stress, or for behavioral reasons. Your veterinarian can run diagnostics to rule out any medical causes of the increased thirst, then can discuss solutions to address the psychogenic polydipsia. They may recommend mental stimulation through toys or games, increased activity if your dog is mostly sedentary, anti-anxiety medications, or other treatments.

Daily Water Requirements for Dogs

How much water is recommended for a dog? You can estimate the daily amount by following this guideline: your dog should drink approximately 1 ounce of water for every 1 pound of their body weight every day. That means a 20-pound dog should consume around 20 ounces (or 2.5 cups) of water each day.

Although this number can give you a good idea of what is appropriate for your dog, it's important to ensure dogs always have access to an abundant supply of fresh water. Active dogs, dogs in hot climates, nursing mothers, and puppies may require more water than this baseline formula suggests.

How Much Water Is Too Much?

A dog's water intake becomes "excessive" when they drink significantly more than their estimated daily requirements. If your dog polishes off the entire bowl of water each time you refill it, or you find yourself forced to replenish their supply several times each day, this may be a cause for concern. Try to measure and document just how much water you offer your dog each day and compare it to the benchmark calculation above.

Dog drinking water from container at playground

Even if your dog drinks water excessively, never limit their access -- doing so could lead to dehydration or dangerous electrolyte imbalances. Instead, call your veterinarian to report the behavior and bring your pet in for an exam.

When to Seek Veterinary Care

Increased water intake alone could absolutely be reason enough to schedule a check-up with your veterinarian. Many of the diseases mentioned above present initially with excessive thirst, then other symptoms pop up as the condition progresses.

Excessive drinking coinciding with other symptoms could indicate a more severe problem. If your dog is drinking more and exhibiting any of the following signs, be sure to see your veterinarian.

  • Changes in appetite (increased or decreased)
  • Urinating in the house
  • Potbellied appearance
  • Hair loss
  • Vomiting
  • Diarrhea
  • Lethargy
  • Weight loss
  • Weight gain
Veterinarian with Small Puppy

Be Proactive

Any noticeable changes in water intake, whether an increase or decrease in drinking, could indicate internal physical changes. Because pets can't verbally tell you what's wrong, you must rely on diagnostic tools to determine what the cause could be. It's always best to catch things early. Ensure that you're proactive in recognizing unusual signs and seek care from a veterinarian to help prevent the progression of dangerous conditions.

Trending on LoveToKnow
12 Potential Causes of Excessive Thirst in Dogs