FRMy pet is drinking and peeing a lot: the change is what counts, not the number
You are refilling the bowl more often, the litter clumps are bigger, or your dog is asking to go out at night. Drinking a lot and peeing a lot are one sign seen from both ends: the body is losing water, and your pet is replacing it. Sometimes the reason is ordinary. Often it is the first clue to a kidney problem or diabetes, a thyroid problem in cats or Cushing's syndrome in dogs, well before your pet looks sick. This page tells you when to go, when to call today, and how to arrive at the appointment with numbers and a urine sample that genuinely help us.
This guide helps you triage; it does not replace your veterinarian's exam. Never take water away from a pet who is drinking a lot. When in doubt, call us at 514 223-1197, or a 24/7 emergency centre if we are closed.
Go now: the signs that cannot wait
Any single one of these is enough. You do not have to tick several, or decide which is worst. Do not wait to see if it passes, do not wait for morning: head to the clinic during our opening hours, or to the nearest 24/7 emergency centre if we are closed. Let them know you are coming: have a passenger call, or use hands-free.
What you can see
- He cannot stay standing, he is staggering, or he collapsed; or he is so weak he barely responds.
- He is trembling, having a seizure, seems disoriented, or is pressing his head into a wall or a piece of furniture and staying there.
- He is breathing fast or with effort while lying quietly. In a cat: breathing with the mouth open.
- He loses his sight suddenly: he bumps into things, his pupils stay wide and fixed, he hesitates in a room he knows by heart. In an older pet who is drinking a lot, our first thought is blood pressure that has climbed too high, and time counts for his vision.
- He was drinking and peeing a lot, and now he is barely drinking, or barely peeing, or not at all (in a cat: far fewer clumps, or none in a clean box). That is not an improvement.
- He is straining to pee and producing almost nothing. A few drops are not reassuring: a passage that is closing lets drops through first. Or he was straining and has stopped without a real stream ever coming out: that is not an improvement either. This is not a pet peeing a lot; he may be blocked, and it cannot wait. Our Blood in the urine page covers it in detail.
- Yellow is showing on his gums, on the whites of his eyes, or inside his ears. Urine that has turned dark, the colour of strong tea, counts the same.
What you already know about him
- He is drinking a lot, whether it started lately or weeks ago, and now he is vomiting, off his food, weak, breathing badly, or his breath smells oddly sweet. Diabetes going off the rails often starts like this, even in a pet whose diabetes is not yet known. If he is already diabetic and on insulin, the next line is the one that applies.
- He is diabetic, on insulin, and eating less or not at all: call before the next injection, even in the evening, even if it is due in an hour. Do not decide on your own to give the dose or to skip it: if we are closed, call a 24/7 emergency centre that same evening. If he is also weak, disoriented, vomiting, breathing fast, or his breath smells oddly sweet: leave right now.
- Your cat is diabetic and takes his treatment by mouth, with no injections, and he is eating less, suddenly drinking less, hiding, vomiting or just not himself. Follow the sheet that came with his medication, go, and tell the team he is diabetic and what he takes: bring the packaging.
- He is being treated for Cushing's syndrome, and he is eating less, vomiting, getting weak or listless: do not give the next dose, and call before you leave: us during our hours, a 24/7 emergency centre if we are closed. These signs can mean his cortisol has dropped too low.
- He may have swallowed or licked something toxic, even a day or two ago: antifreeze, lilies (cats: the flower, a leaf, pollen on the coat, the vase water), grapes or raisins, rat or mouse poison, a psoriasis cream, a human medication. Several of these make a pet drink and pee a lot before they reach the kidneys, often after vomiting or listlessness: do not wait for thirst, and looking better for a while is not reassuring. Do not make him vomit, and bring the packaging or a piece of the plant.
- She is an unspayed female, dog or cat, who is drinking a lot and is listless, eating less, vomiting, has a swollen belly or any discharge. It does not matter how long ago her last heat was. A uterine infection does not always produce visible discharge, and the form without discharge is the more dangerous one.
One is enough. You do not have to work out which of these matters most. If even one applies, go. Two lines are the exception and ask you to call before you leave, and they say so in their own text: the diabetic pet on insulin who is eating less, and the dog treated for Cushing's. If you are unsure, call anyway: triage is our job, not yours. Outside our hours a 24/7 emergency centre answers, and describing the situation on the phone commits you to nothing.
While you get ready. Do not take his water away. And do not delay leaving to collect a urine sample: it is taken at the clinic, and that is where it is most useful. If he may have swallowed something toxic, the animal poison control lines are on our emergency page.
Normal or not: the change is what counts
How much a pet drinks varies a lot from one animal to the next, and from one day to the next. Veterinary references all stress the same point to owners: what matters first is a change from your pet's own habits, more than any number.
Even when healthy, he drinks more when
- it is very hot, or he has been very active;
- he switched from wet food to kibble: for as long as he eats kibble, he drinks from the bowl the water his food no longer gives him;
- he eats a bladder diet designed to make pets drink;
- she is nursing;
- he just had diarrhea;
- he is on a treatment that makes pets drink (section 7).
Those reasons explain a single day, or a change you can put a date on. They do not explain thirst that builds up over weeks: even if it's hot out, tell us.
What is not an explanation
Age: in an older pet, rising thirst is often the first clue to a kidney problem or diabetes, a thyroid problem in cats or Cushing's in dogs. And getting used to it: thirst that creeps up slowly soon looks "normal" to everyone in the house. Ask yourself instead whether you are filling the bowl more often than a few months ago.
The cat on wet food
A cat who eats mostly wet food drinks very little from the bowl, and that is normal: his water is in his dinner. In that cat, simply seeing him at the bowl more often is already a change.
The clues, with no measuring at all
- Any pet: the bowl empties faster; he drinks from the tap, the shower, the toilet or puddles.
- In a cat: bigger or more numerous clumps, a soaked litter box.
- In a dog: more frequent trips out or trips at night, large puddles, accidents after being reliably house-trained, a wet patch where he slept.
What about the number?
We do not publish "normal" amounts or cut-offs. They shift with diet, and a pet can be drinking clearly more than usual well before reaching the figures that circulate online. Measure (section 5): we will do the math with his weight.
Peeing a lot, or peeing often?
These are two different problems, and they lead to different places. A pet who pees a lot also goes to the box or outside more often: what tells them apart is the amount each time, and the effort.
| What you see | What it means |
|---|---|
| Big clumps or large puddles, a bowl that empties faster, no effort at all. | He is peeing a lot. That is what this page is about. |
| Several small clumps, trips back and forth, licking, or blood. | That is the bladder or the urethra, and our Blood in the urine page (in a cat, also Lower urinary tract disease): call today, us during our hours, a 24/7 emergency centre if we are closed. If he strains or cries while trying and nothing comes out, or only a few drops: go now (section 1). |
| A wet patch where he slept, without him noticing. | Urine leaking, common in spayed female dogs. Bring it up at the appointment, and tell us if he is drinking more: drinking a lot makes leaking worse. In an unspayed female, that wet patch may be a discharge from the uterus: if she is drinking a lot, that is section 1, go. |
| In a cat, small amounts sprayed on a wall or furniture, standing, tail quivering. | Marking. Our guide Reduce inappropriate elimination helps you tell the difference, ruling out a medical cause first. |
| He is peeing in the house after being reliably clean. | Any of the four. It is never misbehaviour, and never a reason to take his water away. |
You do not have to sort it out alone: describe what you see. A photo of a litter clump next to an object of known size helps us a great deal.
Today, or an appointment
Below the signs in section 1 (Go now), there are two levels left. No line says "keep an eye on it": the lowest level on this page is an appointment. When two lines apply, go with the more urgent one.
Level "Call today"
(if we are closed, a 24/7 emergency centre)
- She is an unspayed female drinking more than usual, even if she is eating and seems fine, and even with no discharge.
- It came on suddenly, over a few days. If he may have swallowed a product from section 1, go now. Chocolate, in a dog: our My dog ate chocolate page tells you, from the amount, whether to call or go.
- He has been drinking a lot for weeks and, lately, he is eating a little less, without vomiting and without being listless. If he vomits, stops eating or turns weak: go now (section 1). See also My cat stopped eating, My dog stopped eating and My cat is vomiting.
- He is a puppy or a kitten. If he is also listless, vomiting, off his food or staggering: go now, to us during our hours, otherwise to the nearest 24/7 emergency centre.
- He is diabetic and on treatment, and he has started drinking a lot again, even if he is eating and seems well: his treatment may need adjusting (see Handle and administer insulin).
- He is on an anti-inflammatory for pain or arthritis (not a steroid), such as the one sent home after surgery, and has been drinking more since: it may be the kidneys. If he is also vomiting, eating less or passing black stools, follow the sheet that came with the medication and go now, with the packaging: to us during our hours, otherwise to the nearest 24/7 emergency centre.
- He is already being treated or monitored for kidney, liver or thyroid disease, Cushing's syndrome or Addison's disease, and his thirst changes noticeably, up or down.
Level "Book an appointment"
(and start the section 5 sheet while you wait)
- He is well, eating as usual, not losing weight, and the thirst has built up gradually. Call to set a date: this is not a visit to save for the next annual exam.
- He is drinking a lot and losing weight, or eating more than usual, while still bright and eating well: this is the appointment not to put off. The date is set during the call; our My cat is losing weight page explains why. If he eats a little less, that is the level above; if he vomits, stops eating or turns weak: go now (section 1).
- He is on a treatment known to make pets drink, and he is well. Tell us, and do not stop anything (section 8).
- It was very hot and his thirst does not come back down with the heat, or his food changed and he is drinking more than that change explains.
When we are closed
"Today" stops meaning much once the evening comes. If we are closed, call a 24/7 emergency centre: they triage over the phone too, and they will tell you honestly whether this holds until morning. Do not let the clock make the decision for you.
Measuring what he drinks
A measurement taken at home beats a guess, and often beats one taken at our clinic, where a stressed pet sometimes drinks less. It prepares the appointment, it does not replace it: book first, then measure.
Water stays freely available the whole time, day and night. We are measuring what he drinks; we are not deciding what he drinks.
The method, in four steps
- At the start: mark a line on his bowl (a strip of tape on the outside is enough), pour water in with a measuring cup up to the line, and write down the millilitres.
- At every refill, top it back up to the same line with the cup, and write down the millilitres added. It is the step from our My cat is losing weight page, with a number added.
- Twenty-four hours later, at the same time, pour what is left into the cup and write it down, then fill the bowl again for the next day. What he drank is everything you poured in, minus what is left; or leave the math to us.
- Three days in a row. A single day is already worth something: bring the sheet, even if it is not finished.
What throws the measurement off
- Several bowls, several pets, a cat who goes outside: measure each bowl, and the household total if the water is shared (note it in the "Shared bowl" box). Only separate your pet if he is fine with it. A cat who goes outside, or shared litter boxes, make the measurement incomplete, and that is fine: write it down, and tell us what you see.
- Water drunk elsewhere: at home, close the toilet lid and write down the tap or the shower rather than forbidding them. Outdoors it is the opposite: do not let him drink from puddles or eat roadside snow (antifreeze, salt, leptospirosis; see Getting through a Montreal winter), and write down if he ate snow.
- A fountain: measure what you pour into the reservoir, then what is left.
- Nothing new for three days: the same food (note any wet food given), the same bowl, no flavoured water, and water in the wet food only if you usually add it.
- Heat: a heat wave or a very active day changes how much a pet drinks, even a perfectly healthy one. Measure on ordinary days; if the heat arrives partway through, write it on the sheet rather than quietly starting over.
On the urine side, the same days
- Cat: the number of clumps and their size, or a photo of a clump next to an object of known size.
- Dog: his trips out to pee, waking at night, accidents, wet patches where he sleeps.
His weight
Write down his weight if you know it, with the date. If not, we will weigh him: his weight is what turns your millilitres into a number that means something.
The "Measure what he drinks" sheet
One page to put on the fridge and fill in by hand over three days. It prints in black and white, without the rest of the page, and nothing is stored in your browser.
- Name ______
- Dog / Cat
- Known weight ______ kg, on ______
- Food: kibble / wet / both
- Bowl shared with ______ other pet(s)
- Goes outside: yes / no
- Current treatments (as written on the label) ______
- The bowl holds ______ ml up to the line.
- Pour with the cup up to the line.
- At each refill, with the cup: write down the ml added.
- After 24 hours, at the same time, measure what is left, then fill again.
- Three days in a row; a single day is already worth something.
| Day 1, Day 2, Day 3 | Start (date, time) | Poured at start (ml) | Added (ml, at each refill) | Left after 24 h (ml) | Drank (ml) | Other water seen (snow eaten included) | Wet food given | Heat, activity, vomiting, spilled bowl, fluids | Urine (cat: clumps, number and size; dog: trips out, night, accidents) | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| Day 1 | ||||||||||
| Day 2 | ||||||||||
| Day 3 |
On the morning of the appointment, the first urine of the day, in a clean container with a tight lid (we can give you one). The night before, keep his routine: his trips out, his litter box, his water. Brought in as soon as you can; otherwise in the fridge, never the freezer.
Collected on ______ at ______ · Refrigerated: yes / no.
- he collapses or has a seizure;
- he breathes fast or with effort at rest;
- he strains to pee and produces almost nothing, or was straining and stopped;
- he was drinking and peeing a lot and is now barely drinking or peeing;
- he is drinking a lot and is vomiting, off his food or turning weak;
- she is unspayed and becomes listless, vomits, eats less, has a swollen belly or a discharge;
- he is diabetic and vomiting, weak, breathing fast or his breath smells oddly sweet;
- he may have swallowed something toxic.
Forget the sheet and the sample then. During our hours: the clinic. Closed: a 24/7 emergency centre (montreal.vet, 24/7 centres page). If in doubt, call: triage is our job.
The urine sample
Along with the water measurement, this is what helps us most. Urine shows how well the kidneys can still concentrate it, and we check it for sugar, protein and cells: a blood test alone cannot tell us that.
The instructions
- When: on the morning of the appointment, the first urine of the day.
- How: follow our guide Collect a urine sample or, for a cat, the collection kit. We can give you the container.
- The night before: keep his routine. A dog who asks to go out at night goes out, and a cat keeps his litter box where it always is (with the kit, you swap the litter in his usual box the evening before). The morning urine is simply the first one after he wakes up.
- Water: freely available the evening before and overnight. Never take it away to get "more concentrated" urine.
- Storage: tightly closed, brought in as soon as you can; if it has to wait, in the fridge, never the freezer. Write down the time it was collected: it matters for the analysis.
- What it cannot do: a urine culture (the search for an infection). That usually takes urine collected here, straight from the bladder, with a fine needle, and it then goes to an outside laboratory.
A sign from section 1? Forget the sample: it is taken at the clinic.
What it can be
Drinking and peeing more does not point to a single disease: several do it, and only the exam and testing, blood and urine first, tell them apart. In dogs, the most common causes are the kidneys, diabetes and Cushing's syndrome. In cats, they are the kidneys and diabetes, and, in older cats, the thyroid.
- Tiring kidneys (dogs and cats): they no longer concentrate urine well; the body makes more of it and the pet drinks to keep up. It is often one of the first signs you can see; in cats, though, weight loss and muscle loss often come even earlier, without anyone noticing. Chronic kidney disease in cats · Kidney disease in dogs
- Diabetes (dogs and cats): he drinks and pees a lot and loses weight; he often eats more, but in cats appetite can also drop. It is not confirmed at home, or on a single blood test: in cats especially, stress alone can push blood sugar up. Diabetes in cats · Diabetes in dogs
- An overactive thyroid (older cats): he loses weight while eating a lot, turns restless, drinks more. It can hide kidney disease. Hyperthyroidism in cats · My cat is losing weight
- Cushing's syndrome (dogs): thirst, appetite, a rounding belly, thinning coat, panting, all coming on slowly. It does not usually cause vomiting or a loss of appetite: a dog who drinks a lot and is vomiting or eating less probably has something else going on, and needs to be seen today: call us, or a 24/7 emergency centre if we are closed. If he is already being treated for Cushing's, those signs may come from the treatment: that is section 1. Cushing's syndrome
- A uterine infection (unspayed females): in female dogs, new thirst is often how it starts, with or without discharge; in cats, thirst is less consistent. It is a surgical emergency. Pyometra in dogs · Pyometra in cats
- The liver (dogs and cats), and Addison's disease (dogs): other diseases cause thirst along the way, with a falling appetite, jaundice, or bouts of vomiting and weakness. Liver disease in dogs · Liver disease in cats · Addison's disease
- Kidneys hit all at once: antifreeze, lilies (cats), grapes (dogs), vitamin D from rat poison or a psoriasis cream, and leptospirosis, which dogs pick up from puddles, standing water and mud, in any season, and in Quebec mostly from September to December. Depending on the cause: vomiting or listlessness, rising thirst, then kidneys that give out and urine that dwindles. A swallowed product is section 1, without waiting for thirst; a dog who is unwell after drinking from puddles needs to be seen today (if we are closed, a 24/7 emergency centre). Toxic foods and dangerous plants · our emergency page
- Less often: too much calcium in the blood, a kidney infection, and rare causes that are only looked for once the others are ruled out.
- A treatment that makes him drink: steroids (tablets, injections, and even drops or creams in a small pet), seizure medications, diuretics, thyroid hormone at too high a dose, some bladder diets; and fluids given under the skin, which mostly make him pee more (write down the fluid days; see Administer subcutaneous fluids). It is often expected: do not stop anything, do not skip a dose, write it down and tell us. Anti-inflammatories for pain or arthritis, on the other hand, do not usually make a pet drink: if he has been drinking more since starting one, call today: us during our hours, a 24/7 emergency centre if we are closed.
A possible cause may explain why. It does not change when to call.
Give no home medications
When a pet is drinking a lot, people think "kidneys" or "diabetes", and the pharmacy and the health food store both have products for each. None of them is made for him.
Acetaminophen (Tylenol): Deadly to cats, even a single tablet. There is no safe dose. In dogs it attacks the liver. If your pet has swallowed some, that is an immediate emergency.
Ibuprofen (Advil), naproxen (Aleve), aspirin: Stomach ulcers and kidney damage, in dogs as well as cats, and cats are affected at smaller amounts than dogs. Never a human anti-inflammatory, whatever the reason. And here more than anywhere: a pet who is drinking a lot may already have kidneys in trouble, and these are precisely the products that go after kidneys.
Leftover prescriptions, and another pet's steroids: A prescription is worked out for one animal, one problem and one weight: it does not transfer. And a leftover steroid makes a pet drink on its own: it blurs what we are trying to measure.
Cranberry, apple cider vinegar, cinnamon, "kidney" or "diabetes" products: None of them treats a cause of thirst. Cranberry is aimed at the bladder, and even there, it has not been shown to work in pets.
Pharmacy dipsticks and human blood glucose meters: For "checking" diabetes yourself, they can falsely reassure: several of the little colour squares on the strips are not reliable in animals, and a meter made for people often reads low in cats. If we already monitor his diabetes with a device at home, keep going as agreed: this warning is about diagnosis, not that follow-up.
Nothing new, and here is exactly why
It is not that everything is poison. It is that the time and the place are wrong: whatever you give now changes the very tests that will find the cause, and some products damage exactly the organs we suspect. What he needs is water, freely available, and an appointment.
And do not stop anything either
If he is already on a treatment, do not pause it and do not change the dose because he is drinking more: tell us, and we will look together at whether the treatment has anything to do with it. One exception: if the sheet that came with his medication says to stop it when certain signs appear, follow it and call right away: us during our hours, a 24/7 emergency centre if we are closed.
What we do at the clinic
The first appointment
We weigh him, compare with his file, and examine him from nose to tail; your three days of measurements are part of the conversation from that moment on. The urinalysis can be done here, in our own laboratory: we measure how concentrated the urine is, run a dipstick, and look under the microscope at what settles out. The blood sample is drawn here too, and the core tests can be run in our own laboratory, including a value that tells us about the kidneys, blood sugar and, in a cat aged seven or older, the thyroid hormone.
What may follow
Depending on the case: blood pressure, measured here; a urine culture (the search for an infection), which goes to an outside laboratory, on urine collected here straight from the bladder; more involved hormone tests, drawn here and measured at an outside laboratory; imaging, here as well.
Where the samples go, and when you get answers
Some tests are run here, in our own laboratory, and the result sometimes comes back during the visit itself. Other samples go to an outside laboratory. How long it takes depends on the test and on where it goes: ask your veterinarian which of the two applies and how long to expect, that is the question to ask when the sample is taken.
What to bring
- The measuring sheet, even if it is not finished, and the morning urine sample, with its time.
- His medications and supplements, or their packaging.
- The name of his food, and of his treats.
Drinking more than before?
It is information, not a diagnosis, and it is one of the first things we will ask you about. Keep his water out, call us to set the appointment, and measure while you wait.
Frequently asked questions
Why is my cat drinking so much water?
My dog is getting older and drinking more. Is that normal for his age?
He drinks a lot at night. Can I take the water away in the evening?
How much water should a dog or cat drink in a day?
He is drinking a lot and peeing all over the house. What should I do?
My female dog is drinking a lot. Is that more worrying in a female?
He is on steroids and drinking a lot. Should I stop them?
He is drinking a lot and vomiting, or not eating. Is that serious?
My cat is drinking a lot and losing weight. What should I do?
My puppy (or kitten) drinks a lot. Is that normal?
Also worth reading
Updated October 16, 2026
Drinking or peeing more than before?
Book an appointment, start the sheet the same day, and bring it with the morning urine. If a sign from section 1 shows up, go: to us during our hours, otherwise to the nearest 24/7 emergency centre.