Most dog owners notice increased urination more quickly than they notice increased water consumption. This is because increased urine production often results in a dog needing to go outside more frequently, or to urinate in inappropriate locations or during the night (nocturia). Sometimes, owners will also suspect that their dog is incontinent, although this may or may not actually be the case. Owners can also suspect lower urinary tract disease (bladder infections, bladder stones, etc) because bladder problems can cause symptoms of frequent urination in dogs.
Polydipsia is the medical term for increased water consumption above normal levels.
Polyuria is the medical term for increased urine production above normal levels.
Primary polydipsia in dogs, otherwise known as “psychogenic” polydipsia, is increased water
Secondary polydipsia occurs secondary to a medical condition that has caused increased urine production
It is important to note that increased thirst can occur from exercise, increased environmental temperature, pain, etc., however the volumes consumed should be within a “normal” range. Filling a water bowl from a measuring jug and recording the volumes in a 24/48 hour period can be useful to establish whether the increased thirst is temporary or on-going.
|Kidney failure||Kidney failure|
|Diabetes mellitus||Diabetes mellitus|
|Uterine infection (called pyometra)||Hyperthyroidism|
|Leptospirosis||Uterine infection (pyometra)|
|Cushing’s disease||Liver disease|
|Hypothyroidism||High blood calcium|
|Liver disease||Rare abnormalities of the pituitary gland|
|Addison’s disease||Nephrogenic diabetes insipidus (inability of kidney to reabsorb water properly)|
|Pyelonephritis (kidney infection)|
|High blood calcium|
|Hypokalemia (low potassium)|
|Nephrogenic diabetes insipidus|
|Psychogenic polydipsia (behavioral increase in water consumption)|
|Medications (corticosteroids, phenobarbital, furosemide, etc.)|
Diagnosing Causes of Polyuria and Polydipsia
Diagnosing the cause of polyuria and polydipsia may require multiple tests such as
- Urinalysis: A sample taken first thing in the morning is best. The vet will check how dilute/concentrated the urine is as well as analyzing it for evidence of kidney or bladder inflammation that can caused by infection, crystals, or stones. If glucose is found in the urine, this is usually a sign of diabetes mellitus.
- General blood tests: A complete blood count and blood biochemistry are the next step. These blood tests can provide information about the likelihood of systemic infection, liver and kidney insufficiency, endocrine diseases like diabetes mellitus. The list of potential causes is now narrowed down, and additional blood tests or imaging studies may be recommended to hone in on a final diagnosis.
- Specialized blood tests & urine tests: Additional tests may be used to rule in or out causes of pu/pd that are suspected on the basis of early screening test results.
- Imaging studies: X-rays or ultrasound examinations may be used to look for evidence of organ disease, for example cancer.
Once your vet has reached a diagnosis, a treatment plan with expected outcomes can be planned. In a number of conditions, the outcome can be more favourable the earlier the disease is detected, so if you suspect your pet is drinking more than is acceptable, contact your vet for a consultation and clinical examination.
NOTE: Never withhold water from your pet to prevent excessive drinking and urination, because this could result in life-threatening dehydration!