What does it mean when an older dog drinks a lot of water?

Disclaimer: This article, its content, and its related references do not constitute veterinary advice and should not be considered a substitute for veterinary care. If your pet is showing any symptoms that could indicate a medical emergency, please seek immediate emergency care.

Excessive drinking (polydipsia) is a common clinical sign with many potential causes. Many medical conditions of middle-aged and senior dogs are associated with excessive thirst, such as diabetes, kidney disease, and Cushing’s disease. If your senior dog is visiting their water bowl more often than usual, read on to learn:

• Common causes of increased thirst in senior dogs
• Additional symptoms to be aware of
• How much fresh water a healthy dog should drink
• What to do if your dog is drinking more water than usual

It’s important to talk to a veterinarian if your dog is drinking more water than usual, regardless of their age and even if they appear otherwise healthy. However, it is an especially important concern for senior dogs, as many age-related medical issues can cause excessive thirst.

There are many health conditions that can cause excessive thirst in dogs. Many conditions that cause polydipsia are more common in senior dogs and are considered age-related diseases.

Diabetes mellitus

Canine diabetes mellitus (DM) is a common endocrine disorder that causes high blood sugar levels (hyperglycemia). It’s primarily caused by low levels of insulin in the bloodstream. Excessive water consumption is a prominent clinical sign of diabetes, and finding the water bowl empty more often than usual is often the first sign noticed by dog owners. Other signs of DM in dogs include excessive urination, increased appetite, and weight loss.

Canine diabetes mellitus can often be managed with lifelong insulin injections. Routine meal times, therapeutic diets, and exercise also play a role in managing the disease. If not managed properly, DM can lead to secondary conditions and become life-threatening. DM is typically diagnosed in middle-aged to senior dogs.

Chronic kidney disease

Kidney function tends to gradually decrease as a dog ages due to wear and tear over a lifetime. This leads to chronic kidney disease, also called chronic renal insufficiency.

One of the kidneys' responsibilities is water conservation, which is achieved by concentrating urine to keep the body hydrated. Dogs with impaired kidney function often cannot adequately concentrate their urine, so excessive water is lost in the form of highly diluted, large volumes of urine. This leads to dehydration, causing an increase in water intake.

Along with increased thirst and abnormally large amounts of urine, intermittent vomiting and loss of appetite may also be among the first clinical signs of chronic kidney disease in dogs. Chronic kidney disease is associated with old age in dogs and develops gradually.

With acute kidney injury, such as what occurs suddenly with a kidney infection or ingestion of a toxin, excessive thirst and urination tend to be accompanied by a sudden onset of severe, persistent vomiting and weakness.

Cushing’s disease

Cushing’s disease (hyperadrenocorticism) is caused by elevated cortisol levels, most often due to a tumor. The condition can sometimes be caused by the use of prednisone and other corticosteroids as well. Early signs of Cushing’s disease are often subtle and intermittent, so they can be easily overlooked by pet owners.

Symptoms include an increase in thirst, changes to the skin and fur, excessive urination, and a pot-bellied appearance. Cushing’s disease mainly occurs in senior dogs.

Other causes of excessive drinking in senior dogs

Other examples of diseases associated with excessive water consumption in dogs include:

• Cancer
• Hyperthyroidism
• Addison’s disease
• Pyometra
• Infectious disease

It can also appear as a side effect of some medications.

Because there are so many potential causes of increased thirst in dogs, it’s important to talk to a veterinarian and get an accurate diagnosis.

Increased thirst levels are commonly accompanied by other clinical signs, such as:

• Excessively large volumes of urine (polyuria)
• Increased or lack of appetite
• Unexplained weight loss
• A pot belly, which may appear as weight gain
• Changes to the skin
• Hair loss
• Low activity levels
• Vomiting

A sudden increase in water intake is often the first noticeable sign of various age-related illnesses in dogs. It’s important to talk to a veterinarian if you notice excessive water intake, even if your dog appears otherwise healthy. Looking for other changes in physical or behavioral health can aid in the diagnostic process. “Clinical signs alone are not enough to diagnose which disease is causing polydipsia,” states Dr. Jo Myers, a veterinarian on the Vetster platform. “Urinalysis and basic blood tests are typically necessary, and some cases require more advanced blood work and/or diagnostic imaging.”

Each dog is different, but healthy dogs typically drink approximately 100 ml of water per kilogram of body weight over the course of a day (a little more than one fluid ounce per pound). Talk to a veterinarian if you find your dog’s water bowl empty more than usual or if they’re drinking more often than usual. Being more thirsty than usual after physical activities or exertion is normal and temporary. A dog may also be more thirsty than normal after fasting, such as prior to surgery.

If you’re wondering if your dog’s daily water intake is normal, measure it for a few days so you and your vet can make an objective assessment. A dog who consistently drinks more than normal, even when they’re inactive or it isn’t hot outside, needs veterinary attention. You can consult with an online vet if you’re unsure if the amount of water your dog is drinking is normal and to determine what steps to take next.

Talk to a veterinarian if you notice your dog is drinking more water than usual without an identifiable cause, such as recent exercise. It’s a common sign of illness with many potential causes, some of which become more likely as dogs age. Excessive water consumption is usually accompanied by excessive urination.

A virtual vet appointment may be helpful in determining if your dog’s water intake is normal or not. A vet may recommend diagnostic tests, such as blood work and urinalysis, to check for common causes of increased thirst in senior dogs. Any changes in your dog’s thirst or appetite warrant veterinary attention, even if your dog seems fine otherwise.

What does it mean when an older dog starts drinking a lot of water?

There are many medical issues that are common in senior dogs that can cause an increase in thirst (polydipsia), such as diabetes, kidney disease, Cushing’s disease, and others. In many cases, excessive thirst is the first noticeable clinical sign. It’s important to seek veterinary attention if you notice your dog is consistently drinking more than usual without an identifiable cause, such as recent exercise or hot weather.

What amount is considered excessive drinking in dogs?

Most healthy dogs typically drink approximately 100 ml of water per kilogram of body weight per day (a little more than one fluid ounce per pound). If your dog is drinking much more than this estimate or is suddenly visiting the water bowl more often than usual, a veterinary consultation is warranted to check for an underlying issue.

Should I be worried if my dog is drinking more water than usual?

Suddenly drinking more water than usual for a prolonged period of time may be a sign of an underlying health issue in dogs, even if they seem otherwise healthy. It’s best to talk to a veterinarian if you believe your dog is drinking an excessive amount of water and to check for any underlying conditions that may be causing it.