It’s a question that might pop into your head quietly at first. Is the water bowl emptier than usual? Then you notice it again. Your dog seems to be waiting by their bowl, draining it quickly, and maybe even waking you up at night for a drink or a trip outside. While it could be nothing, a change in your dog's thirst is a symptom no pet parent should ignore.
Excessive thirst, known medically as polydipsia, can be a sign that something is wrong. Understanding what’s normal for your dog is the first step toward catching potential health issues early.
How much water is normal?
So, how much is too much? A general guideline is that weaned puppies and adult dogs need between one-half to one ounce of water per pound of body weight each day. For example, a 20-pound dog would typically need between 10 and 20 ounces of water daily.
That said, other factors can cause your dog to drink more, including:
- Hot weather
- Recent exercise
- A diet high in salt
- Age (puppies often need more water)
- Certain medications, like corticosteroids or diuretics
A dog eating canned food, which contains a lot of water, may naturally drink less than a dog on a dry kibble diet.
When does increased thirst become a red flag?
While occasional increases in thirst are normal, the real concern is a consistent and significant change. "A red flag is when thirst is excessive, persistent, or unexplained," says Primrose Moss, MRCVS, with Spot Pet Insurance. "If your dog is draining their bowl daily, asking for refills constantly, or waking you at night to drink and urinate, it's time to call your vet."
No matter what, you should never deprive your dog of water unless a veterinarian specifically directs you to do so. Withholding water can lead to dangerous dehydration and electrolyte imbalances.
Common Medical Causes of Excessive Thirst
If you've ruled out environmental factors, it’s time to consider underlying health conditions. "The most common culprits are diabetes, kidney disease, and Cushing's disease," says Dr. Moss.
Here’s a quick look at these conditions:
- Diabetes mellitus: This occurs when a dog's pancreas doesn't produce enough insulin, leading to high blood sugar. The body tries to flush this excess sugar out through the urine, which pulls a large amount of water with it, causing dehydration and intense thirst.
- Kidney disease: When the kidneys can't filter waste products efficiently, the body produces more urine to try to remove the toxins. This loss of fluid makes the dog drink more to compensate.
- Cushing's disease: Caused by the overproduction of the stress hormone cortisol, this condition directly leads to increased thirst and urination.
Another life-threatening condition to be aware of in unspayed female dogs is pyometra, a uterine infection that can be fatal if left untreated. Its toxins affect the kidneys' ability to retain water, leading to increased urination and thirst.
"Key symptoms include increased urination, weight loss or gain, changes in appetite, vomiting, or lethargy," says Dr. Moss. "If thirst is paired with any of these, see your vet promptly."
How can I encourage healthy hydration?
While a serious change in thirst warrants a vet visit, ensuring your dog has access to fresh, appealing water is always important. If you're looking for ways to encourage healthy drinking habits, here are a few tips:
- Keep it clean. Make sure their water bowl is clean and regularly fill it with fresh water.
- Consider placement. Place water bowls near their food, bed, or anywhere they like to hang out.
- Use a pet water fountain. The sound and motion of running water can be more enticing for some dogs, encouraging them to drink more often.
- Offer ice cubes. Some dogs love chewing on ice cubes, which is another easy way to increase their water intake.
Preparing for Your Vet Visit
If you decide to make an appointment, a little preparation can make a big difference. "Track your dog's water intake (in cups or ounces), urination frequency, appetite, and energy level for a few days beforehand," says Dr. Moss. "Note when the change began. These details can help your vet diagnose more quickly."
Your vet will perform a physical exam and likely recommend diagnostic tests. "A urinalysis can reveal sugar in the urine (a diabetes indicator), infection, or kidney trouble," explains Dr. Moss. "Bloodwork checks kidney function, blood sugar, and hormone levels. Together, these give a clear picture of what's happening inside your dog's body."
The Most Important Takeaway
When it comes to a sudden change in thirst, the best advice is to act. "Don't wait too long," says Dr. Moss. "If thirst changes last more than a day or two or are paired with other symptoms, call your vet immediately — early detection is key."