TL;DR: Excessive thirst and urination in dogs often indicate underlying health issues like diabetes or kidney disease; schedule a veterinary appointment within 24 to 48 hours unless accompanied by lethargy or vomiting.
What do polydipsia and polyuria mean for my dog’s health?
Polydipsia refers to excessive thirst or drinking, while polyuria refers to the production of an abnormally large volume of urine. These two conditions almost always go hand-in-hand because as a dog drinks more, their body must eliminate the excess fluid. This can be a sign of various underlying health issues, such as diabetes mellitus, kidney disease, or Cushing's disease.
How urgent is it if my dog is drinking and urinating more than usual?
- Increased drinking and urination are generally considered symptoms of medium urgency.
- Schedule a veterinary examination within the next 24 to 48 hours.
- If your dog is also showing signs of lethargy, vomiting, or a loss of appetite, contact an emergency clinic immediately.
How can I help my vet by documenting my dog’s symptoms at home?
- Share photos of your dog's urine on a light surface or a puppy pad to help identify abnormalities like cloudiness, blood, or extreme dilution.
- Keep a log of how many times you refill the water bowl to provide measurable data on water consumption.
- Provide this visual and documented evidence to your veterinarian to ensure a faster and more accurate triage process during your consultation.
Clinical Context (Merck Veterinary Manual)
The polydipsia and polyuria (PU/PD) associated with chronic kidney disease must be differentiated from other conditions. These include diseases causing primary polydipsia (e.g., psychogenic polydipsia, hyperthyroidism) or those that interfere with the urine-concentrating mechanism. The latter encompasses 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, diseases causing septicemia). In young patients presenting with PU/PD, psychogenic polydipsia should be considered, ruling out other differentials such as cystitis and crystalluria. If diabetes insipidus is suspected, a 12-hour water deprivation test can assess urine concentrating ability. In cases where water deprivation is contraindicated or inconclusive, a therapeutic trial with desmopressin may be considered after excluding other causes of PU/PD.
Chapter: Nephrology, Endocrinology
Source: The Merck Veterinary Manual, 11th Edition (Page 1514)