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.
Start tracking - it's freeA 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.
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.
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.
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.
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.
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.
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."
General guidance from veterinary sources - increased thirst always warrants investigation. The tracker helps you measure it, it does not decide the cause.
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.
Cat water fountains → Measuring jugs → Pet scales →#ad - affiliate links: as an Amazon Associate, PetHealthLog may earn from qualifying purchases at no extra cost to you. Informational only, not veterinary advice.
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.
Free, offline, and ready the moment you open it.
Start with PetHealthLogIf the worry is too little water rather than too much, track the skin-tent and gum checks alongside intake.
The measurement side: how much a cat should drink, a daily intake log and a baseline you can compare against.
If a vet diagnoses CKD - the most common cause of extra thirst in older cats - track the renal diet, fluids and weight.
Diabetes is another common cause of increased drinking. Log insulin doses and meals to keep treatment on track.
An overactive thyroid can drive both thirst and weight loss. Track the medication and the symptoms that follow.