When a cat suddenly starts emptying the water bowl, it is often the first quiet sign that something is off - long before anything else shows. PetHealthLog lets you log daily water intake, set a baseline, and watch for a rise in thirst, noting urination and weight beside it - so you can bring a vet real numbers instead of "I think she's been drinking more." Free, no account, works offline.
A sudden, unexplained increase in drinking is one of the first signs of illness in a cat - and it frequently shows up while the cat is still eating and behaving completely normally. A common veterinary reference point is that a cat taking in more than roughly 100 ml of water per kg of body weight a day is considered excessively thirsty, or polydipsic. The usual culprits are kidney disease, diabetes and an overactive thyroid, all of which respond far better when they are caught early.
The catch is that thirst creeps up slowly. "She seems to be at the bowl more often lately" is hard to act on and easy to second-guess. One important note: you should never restrict your cat's water to stop the drinking - the extra intake is usually the body compensating for an underlying problem, and limiting it can do harm. The job is to measure the change, not to suppress it.
PetHealthLog is free, asks for no account and works offline, so you can set a baseline and log the daily figure as you go. The trend is right there, a doubling is obvious, and you have a real record instead of an impression when you call the vet.
What the thirst tracker actually does
A water log only helps if it is quick to fill in each day and turns a vague feeling into a trend you can show a vet. Here is how PetHealthLog handles both.
Log daily water intake and set a baseline
Record how much your cat drinks each day and lock in a baseline for a normal week. Once that reference exists, any climb stands out - you can see at a glance whether intake has nudged up or roughly doubled.
Spot a rise in thirst early
The tracker lays the daily figures out over time, so a gradual increase that is invisible day to day becomes an obvious upward line over a fortnight. Catching that early is exactly what gives kidney disease, diabetes or thyroid trouble the best chance of being managed well.
Note urination, litter changes and weight
More drinking usually means more or larger wet patches in the litter, and weight often shifts with the conditions behind it. Log litter changes, weight and appetite beside the water numbers so you arrive with the full picture, not a single figure.
Track wet food and other symptoms
Cats on wet food get water from their meals, so a switch in diet can change the bowl figures. Note wet food, any vomiting, lethargy or other changes, so the trend is read in context rather than misread.
A vet-ready report if you need it
Export a clean PDF of the daily intake, the baseline, the trend and the notes. The appointment starts from a real chart of the change instead of "she's been drinking more, I think for a couple of weeks."
Signs that mean book a vet visit
General guidance from veterinary sources - increased thirst always warrants investigation. The tracker helps you measure it, it does not decide the cause.
A clear, sustained rise in drinking, or intake above roughly 100 ml per kg per day
More frequent or larger wet patches in the litter alongside the extra drinking
Weight loss, appetite changes, or a cat that is hungrier as well as thirstier
Lethargy, vomiting, a dull coat, or any drop in your cat's usual self
An older cat, where kidney disease and thyroid trouble are more common
Any sudden, unexplained change in thirst even if the cat seems otherwise fine
Measuring intake without the guesswork
You do not need lab precision to catch a trend - you need consistency. Owners often keep a few simple things on hand: a measuring jug to fill the bowl with a known amount, a pet water fountain that many cats drink from more readily (and that makes intake easier to top up and track), and a kitchen scale for the wet-food side of the equation. The goal is the same daily routine, so the numbers are comparable from one week to the next.
These search links show popular options on Amazon. They are everyday extras for measuring intake at home - what the increased thirst means is a question for your vet.
#ad - affiliate links: as an Amazon Associate, PetHealthLog may earn from qualifying purchases at no extra cost to you. Informational only, not veterinary advice.
Why "free, offline, no account" matters here
Tracking a trend means showing up every day for a couple of weeks, and anything that adds friction is the reason the log quietly stops. The last thing that should stand between you and recording today's figure is a login screen or a paywall.
PetHealthLog stores everything locally on your device. There is no account to create, nothing is uploaded to a server, and there is no tracking. It opens instantly, lets you log intake whether or not you are online, and keeps the data yours. You can export a backup any time and restore it on another phone.
Get started in under a minute
Open the app - no download from a store and no sign-up required.
Add your cat, then log a few normal days to set a baseline you can compare against.
Record the daily water intake, note urination and weight, and watch the trend over the weeks.
Yes. Logging daily water intake, setting a baseline, watching for a rise in thirst, noting urination and weight, and the PDF report are all free to use. There is no sign-up and no account, and your cat's records stay on your own device.
My cat is drinking a lot of water - when should I worry?
A sudden, unexplained increase in drinking is often the first quiet sign of illness in a cat, even one that is still eating and acting normally. A common veterinary reference point is that a cat taking in more than roughly 100 ml of water per kg of body weight a day is considered excessively thirsty (polydipsic). The most common causes in cats are kidney disease, diabetes and an overactive thyroid - all of which are far easier to manage when caught early. Importantly, you should not limit your cat's water to control the drinking, as the extra intake is usually compensating for an underlying problem. A vet needs to find the cause, and a clear record of the change is exactly what helps them. This tracker keeps that record; the diagnosis is always one for your vet.
Why does logging the water intake matter?
Increased thirst creeps up slowly, and "I think she's been drinking more lately" is hard for a vet to act on. A baseline plus a few weeks of logging turns a vague impression into a real trend - so you can show a vet that intake has roughly doubled, or that it climbed over a fortnight, rather than guessing. Because excessive thirst is so often the earliest sign of kidney disease, diabetes or hyperthyroidism, catching the rise early can make a genuine difference to how those conditions are managed.
How do I measure how much my cat drinks?
You do not need to be exact to spot a trend. A simple approach is to fill the bowl with a measured amount each day and note how much is left, accounting for evaporation by leaving a second identical bowl untouched if you want to be precise. Cats on wet food also get water from their meals. The tracker lets you log the daily figure and any wet food, so the day-to-day numbers and the overall direction are there to read. Even rough but consistent measurements reveal a doubling far more reliably than memory does.
Can I note urination and weight alongside the thirst?
Yes. Increased drinking usually goes hand in hand with more or larger wet patches in the litter, and weight or appetite changes often travel with the conditions behind it. You can note litter changes, weight, appetite and any other symptoms beside the water figures, so you arrive with the full picture rather than a single number - which is exactly what helps a vet narrow down the cause.
Is this a substitute for veterinary advice?
No. PetHealthLog is a record-keeping tool, not veterinary advice. It does not diagnose why a cat is drinking more or tell you it is safe to wait. Increased thirst can point to several serious conditions, and finding the cause is a job for a licensed veterinarian - the tracker simply helps you keep an accurate baseline and an honest record of the change so the conversation starts from real numbers.
Informational only - not veterinary advice. PetHealthLog helps you keep records and stay organised, but it does not diagnose why a cat is drinking more or tell you it is safe to wait. Never restrict your cat's water to control the drinking. If your cat's thirst has clearly increased - especially with weight loss, appetite changes, more urination or in an older cat - contact a licensed veterinarian.
An overactive thyroid can drive both thirst and weight loss. Track the medication and the symptoms that follow.
Related buyer guide
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When to contact a vet immediately
A tracker is for patterns over time — it is not for emergencies. Contact a veterinarian or an emergency clinic right away if your pet has difficulty breathing, collapses or cannot stand, has a seizure that does not stop or seizures that repeat, is straining to urinate without producing urine, has severe bleeding, or may have swallowed something toxic (see ASPCA Animal Poison Control).
PetHealthLog is a record-keeping tool, not veterinary advice. Nothing on this page diagnoses or treats any condition — always follow your own veterinarian's guidance.