TL;DR: Excessive drinking and urination (PU/PD) in dogs are signs of underlying health issues and typically require a veterinary evaluation within 24 to 48 hours.
What does it mean if my dog is drinking and urinating more than usual?
When a dog drinks an abnormal amount of water and urinates more frequently than usual, veterinarians call this PU/PD (Polyuria and Polydipsia). This is not a disease itself but a clinical sign that your dog's body is struggling to maintain its water balance. Common causes include diabetes mellitus, kidney disease, Cushing's disease, or even a simple urinary tract infection.
How quickly should I take my dog to the vet for increased thirst and urination?
- Schedule a veterinary evaluation within the next 24 to 48 hours to ensure underlying conditions do not worsen.
- Seek emergency care immediately if your dog is also vomiting, refusing food, or acting extremely lethargic.
What photos or documentation should I provide to help my vet with triage?
- Take a photo of your dog's urine on a light surface to show the concentration or color.
- Photograph your dog's water bowl at the beginning and end of the day to help the vet quantify exactly how much water is being consumed.
- Record a video of any unusual posturing or straining during urination to help distinguish between a behavioral issue and a physical one.
Clinical Context (Merck Veterinary Manual)
The polydipsia and polyuria associated with chronic kidney disease must be differentiated from other conditions causing primary polydipsia, such as psychogenic polydipsia or hyperthyroidism, and those that directly interfere with the urine-concentrating mechanism. These include conditions leading to solute retention in tubular fluid (e.g., diuretic administration, diabetes mellitus), central diabetes insipidus, and nephrogenic diabetes insipidus (e.g., hyperadrenocorticism, hypercalcemia, pyometra, and diseases causing septicemia). If other causes of polyuria and polydipsia are excluded, a monitored therapeutic trial with desmopressin can be performed to differentiate central diabetes insipidus, nephrogenic diabetes insipidus, and psychogenic polydipsia; a dramatic reduction in water intake during the trial suggests an ADH deficiency, indicating central diabetes insipidus or partial nephrogenic diabetes insipidus. In young dogs with psychogenic polydipsia, cystitis and crystalluria should be ruled out. Measuring urine specific gravity before and after a 12-hour water fast can help exclude diabetes insipidus.
Chapter: Nephrology, Endocrinology
Source: The Merck Veterinary Manual, 11th Edition (Page 1514)