This is one of the most useful early signals a dog owner gets, and one of the easiest to explain away as "it's been warm." A clear, unexplained increase in drinking and urinating deserves a veterinary assessment even when your dog seems perfectly well — because several of the conditions behind it are much easier to manage caught early.
Keep water freely available while you arrange that appointment. More on why below.
How we label our evidence
- Source-supportedStated directly in the cited institutional publication.
- Our editorial guidanceA conservative reading of the evidence applied to a caregiver decision. Not a validated clinical protocol.
- Evidence gapWe could not verify this in our approved sources, so we have not invented a number.
Reference numbers
| Measure | Reference | How to use it |
|---|---|---|
| Typical drinking | 40–60 mL/kg/day | Cornell's general estimate. Heat, activity and your dog's own baseline matter. |
| Polydipsia (excessive drinking) | Over 100 mL/kg/day | A trigger to get assessed — not a diagnosis, and not a line below which illness is ruled out. |
| General water requirement | ~44–66 mL/kg/day | Merck, under thermoneutral conditions, including water from food. Wet-fed dogs drink less. Don't add this to the drinking figure above. |
| Urine output (clinical monitoring) | 1–2 mL/kg/hour | Roughly 24–48 mL/kg/day. This is a clinical reference, not a normal number of toilet trips. |
Evidence gap
A commonly quoted outpatient threshold of "more than 50 mL/kg/day of urine" was not established in our approved sources, so we haven't used it. Also worth separating: urinating more often and producing more total urine are different observations with different meanings. Record both rather than calling every extra trip polyuria.
Measuring without restricting
If your dog is well enough to stay home while you arrange the appointment:
- Over an ordinary 24 hours, record all water put into bowls and fountains, including refills. Subtract what's left. Note spills, shared bowls and any outdoor drinking you can't measure.
- Divide: mL ÷ body weight in kg. For example, 1,200 mL in a 10 kg dog is 120 mL/kg/day.
- Record food type, amount and moisture, plus any water added to food, separately from measured drinking. Switching wet to dry food changes bowl consumption on its own.
- Note onset, appetite, body weight, energy, medication changes, heat and exercise, any accidents, and whether urinations are larger or just more frequent.
Emergency now
Never make water inaccessible to get a cleaner measurement, or to stop overnight accidents. Restriction can cause dehydration and dangerous electrolyte disturbances. Start the record while seeking care — don't postpone the call to finish it.
What it can mean
| Possibility | Clues |
|---|---|
| Kidney disease | Lost urine-concentrating ability raises both output and thirst. Weight loss, vomiting or reduced appetite increase concern. More common with age, but young dogs get it too. |
| Diabetes mellitus | Thirst and urination up, often with weight loss despite a good appetite. Diagnosis needs laboratory evidence — thirst alone isn't enough. |
| Cushing syndrome | Usually middle-aged or older. May come with increased hunger, panting, a pendulous abdomen, muscle loss and skin changes. |
| Pyometra (infected uterus) | Intact females, often 1–2 months after a heat. Discharge may occur — but a closed cervix can mean no discharge at all. This is an emergency. |
| Other | Infection, liver disease and other hormonal disorders. Diet and medication history matter. |
When to act
What the action labels mean
- Emergency now —
- contact an emergency veterinary service and arrange immediate assessment. Do not wait for the next scheduled feed or weigh-in.
- Call now for triage —
- telephone the veterinary service when you notice the sign. The veterinarian decides how quickly the animal needs to be seen.
- Contact today —
- get in touch when you notice the issue to agree on a time. This does not mean waiting until evening.
Emergency now
Straining without passing urine, or bloody or painful urination.
Emergency now
Increased thirst plus vomiting, marked lethargy, weakness, or a swollen or painful abdomen in an intact female — particularly after a recent heat. Suspect pyometra even with no vaginal discharge.
Emergency now
A known or suspected diabetic dog becoming clearly unwell: vomiting, refusing food, pronounced weakness or dehydration. Diabetic ketoacidosis can occur before diabetes is even diagnosed.
Call now for triage
The change is abrupt, pronounced, or worsening quickly; there's new vomiting or reduced appetite; the dog already has kidney disease or diabetes; or an intact female recently had a heat.
Contact today
An otherwise bright dog with a clear, unexplained increase from its own baseline, new indoor accidents, or measured drinking above the threshold. Book an examination rather than changing the food or cutting water.
Two myths
- "Take the water away overnight to stop accidents." Covered above — this is actively dangerous.
- "Under 100 mL/kg/day means healthy; over it means diabetes." The cutoff neither clears a symptomatic dog nor identifies a cause.
If your dog is older, this sits alongside the other changes worth flagging rather than attributing to age — see when is a dog actually a senior.
Sources
- Cornell Riney Canine Health Center Canine Polyuria and Polydipsia (April 2024)
- Merck Veterinary Manual Renal Dysfunction in Dogs and Cats
- Merck Veterinary Manual Nutritional Requirements of Small Animals
- Merck Veterinary Manual Cushing Syndrome (Hyperadrenocorticism) in Animals
- Cornell Riney Canine Health Center Pyometra
- AAHA 2026 Diabetes Management Guidelines for Dogs — Sections 2 and 3
- Merck Veterinary Manual When to See a Veterinarian