Water Levels That Indicate Your Dog Is Drinking Too Much

Extra refills of your dog's water bowl are rarely a worry on their own. Dogs drink more in hot weather, for example, and after a switch from wet food to dry.

Drinking that stays high for several days is different. It can be an early sign of a health problem such as kidney disease, and it helps to know how much your dog is really drinking before you call your vet.

That figure is simple to get. Measure what your dog drinks over two ordinary days, then compare it with the amount vets treat as too much for a dog of that weight. With our own dogs, a run of extra refills has usually turned out to be a hot week. We measure before we worry.

The sections that follow show you how to measure and what to rule out first. The last part of the guide explains when a high figure means calling your vet the same day.

The Normal Amount And The Too-Much Line

The line we use comes from Cornell's Riney Canine Health Center, which treats anything over 100 ml for each kilo as excessive thirst, or polydipsia, against a normal 40 to 60 ml. Both figures scale with body weight, so a Labrador lapping up many times what a Chihuahua does can still be well inside normal.

 If you think in ounces, the too-much line works out at a little over 1.5 fl oz per pound each day, about 77 fl oz at 50 lb. That's the Riney Center's 100 ml a kilo spread across 24 hours, or more than 4 ml per kilo every hour.

Your Dog's Own Normal Matters Most

The normal ranges for how much a dog drinks were worked out on laboratory-reared dogs kept under controlled conditions. Your dog's life looks nothing like that, so its drinking won't either. A dog on wet food can drink near the bottom of the range for years, while a busy kibble-fed dog with a high activity level lives near the top.

So the comparison that tells you most is how much your dog drinks now against its own usual amount. Drinking that has doubled in two weeks deserves a closer look even if it is still under the line. A steady figure just above it, in a dog that has always drunk that way, worries us far less than a sudden jump in how much it drinks.

Measure Your Dog's Intake Over Two Days

To see how much water your dog really drinks, pick two ordinary days at home with the usual food and walks. It's the quiet-day setup vets suggest for this check, because a hot spell or a long hike would inflate the total for reasons that have nothing to do with health.

1. Fill your dog's only bowl from a measuring jug, more than it can finish, and mark the level.

2. Close the toilet lid, keep your dog away from puddles in the yard and move other pets' bowls out of reach.

3. At the same time the next day, top the bowl back up to that level and write down the amount you added as your dog's intake for the day.

4. Repeat on day two, add the two top-ups together and halve the total to get what your dog drinks in a day.

5. Check that daily water intake against the table, or divide it by your dog's kilos to compare with 100 ml.

Say those two days add up to 3,300 ml of top-ups, all drunk by your 33 lb (15 kg) dog. Halved and divided by 15, that comes to 110 ml a kilo, which is past the line, so rule out the everyday causes below before you call your vet.

That works for one dog. If two dogs share a bowl, you'll only ever measure how much water they drink between them. For the two days, give the dog you're worried about its own water bowl in its own room, which also tells you whether the extra drinking is coming from that dog.

Rule Out Food And Medicine First

Check what has changed in your dog's food and medicine before you treat a high figure as too much. In our experience a new diet and a new prescription are the two everyday reasons that catch owners out most, because a switch made two weeks ago rarely gets connected with this week's refills. Exercise or hot weather pushes intake up too, but that rise fades once your dog has cooled down.

Dry Food Means More From The Bowl

When a dog moves from wet food to dry food, its total water for the day barely changes, but the share it used to get from its meals now has to come from the bowl.

In a study that weighed dogs' bowls at home, the dry-fed dogs took 44.5 ml a kilo each day from them, against 23 ml for those on a wet and dry mix. Those dogs drank most in the evening, so an empty bowl at bedtime is no warning sign on its own.

A food change explains a jump of that size by itself, so if you've just switched to kibble, run the two-day check again once your dog has been on it for a couple of weeks.

Steroids Raise Thirst

Prednisone and prednisolone are the steroids vets prescribe for itching and inflammation. They make a dog pass more urine, and thirst follows. Even a short course commonly shows up as more refills, and sometimes as accidents from a dog that has been reliably house-trained for years.

Some seizure medication and diuretics raise thirst too, so if the drinking started within days of any new medication, call the vet who prescribed it. Keep giving the medicine under your vet's guidance until they say otherwise.

Boredom Is Rarely The Reason

We'd rarely put a young dog drinking a lot of water down to boredom, however much energy it has to spare. Psychogenic polydipsia, the behavioral form, is uncommon in dogs and only comes up once every physical cause has been ruled out. Any dog given that diagnosis is treated with its vet's help, never by rationing the bowl at home.

A Water Bowl That Shows How Much Your Dog Drank

Two days with a measuring jug is fine for a one-off check. A bowl with a known capacity and a visible level makes later changes easier to spot. The DoggySpout Wireless Fountain holds 4 liters (135 oz) and shows its water level, so you can see at a glance how fast the tank is going down. Once you know how many days a full tank usually lasts your dog, a tank that runs dry days sooner stands out. Run a proper two-day check when that happens.

It runs on a rechargeable battery, so it can sit wherever your dog actually drinks and become the one bowl you're measuring. Bigger dogs are better suited to the 7-liter (236 oz) size. Jot down the date each time you refill it, and you'll have weeks of ordinary refills to compare against when the gap starts shrinking. See the dog fountain that shows its water level and pick the size that fits your dog.

Thirst That Lasts Needs A Vet

Once food, heat and medicine are ruled out, a dog drinking a lot of water for days needs your veterinarian. In most of these dogs the body is losing extra water in the urine first, which vets call polyuria, and the increased thirst is the dog keeping up.

Same Day For Vomiting Or A Recent Season

Skip the two-day check and call your vet today if the extra drinking comes with any of these:

• Vomiting, diarrhea or sudden lethargy, where your dog is listless and uninterested in walks.

• An unspayed female in the weeks after her season. Pyometra, a womb infection that can turn serious quickly, affects about one in five unspayed females by the age of ten.

• A dog that drinks from puddles or ponds and has gone off its food. Leptospirosis, an infection caught from contaminated water, can show up early as increased thirst.

• A swollen belly or wobbliness straight after a long swim, which can be water intoxication and is an emergency.

Book In If The Number Stays High For Days

If your dog is otherwise bright but the figure stays high for several days, book an appointment for this week. A rise that holds steady day after day is a different picture from one bad afternoon, and it's the pattern kidney disease often starts with: extra urination first, weight loss and appetite changes later.

Your dog's age matters too, and in an older dog we'd book the earliest slot we could get. A first-time rise in a dog past middle age is less likely to be food or heat and more likely to be hormonal. Diabetes and Cushing's disease both fall in that group, and a raised blood calcium level or liver disease can drive thirst too.

When thirst comes with weight loss, bad breath or new accidents in the house, kidney disease moves up the list. Mention every one of those when you call, along with any change in appetite.

Keep The Bowl Full Until Then

Taking the bowl away to stop the accidents is an understandable urge, but a dog losing extra water in its urine drinks to stay level, so cutting it back turns your home into an unsupervised water deprivation test. Vets only run that test under close supervision, because some dogs slide into dangerous dehydration within hours. Handle the wet rug with more trips outside, including a late one before bed. Leave the bowl full.

Bring Your Numbers And A Urine Sample

Your vet's first questions will be about timing and routine, so write these down before the appointment:

• When the drinking started, and your two-day figure.

• Any change in peeing or accidents.

• What your dog eats, and every medicine it takes.

Then collect a urine sample in a clean container first thing in the morning, before breakfast or a drink. That sample tells the vet most about how well the kidneys concentrate.

A single reading can swing quite a bit from one morning to the next in a perfectly healthy dog, so your vet may ask for a second one. The first tests are usually a urinalysis, a complete blood count and a chemistry panel. If you're told it's just age before any of those have been run, it's fair to ask for them. Your vet has examined your dog and we haven't, so their call on what comes next is the one to follow.