Veterinarian Column: Drink lots of water and excessive urine output is a sign of illness!

by Alice's Dog & Cat獣医師

Drinking a lot of water (polydipsia) and producing a large amount of urine (polyuria) can be signs of various diseases. This time, we will explain about diseases that cause excessive drinking and excessive urination.

What is heavy drinking?

Polydipsia occurs when you drink more water than is normal.

Normal amount of water to drink per day

Dogs: 20-90ml per 1kg of body weight

Cat: 0 to 45 ml per 1 kg of body weight (water consumption will vary depending on whether the food is dry or wet.)

For example, for a 5 kg dog, the normal amount of water to drink is 100 to 450 ml per day. It is also affected by the heat and exercise, so if the average amount exceeds the normal amount not only for one day but for several days, it is considered excessive drinking.

What is polyuria?

If your daily urine output exceeds 60ml per kg of body weight, you are considered to have polyuria.

Since it is difficult to measure the daily amount of urine every day, it is possible to test the urine specific gravity with a urine test, and if the urine remains dilute, it can be determined that polyuria is present.

Alice's Dog & Cat_Veterinarian Column_Polyuria

What diseases cause polydipsia and polyuria?

·kidney failure




・Hypoadrenocorticism (Addison's disease)




・Liver failure

・Diabetes insipidus

・Psychogenic, etc.

■Kidney failure

Alice's Dog & Cat_Veterinarian Column Kidney Failure

Acute renal failure

Acute renal failure is a life-threatening disease, but with appropriate treatment, kidney function can be restored. Causes include decreased blood flow to the kidneys, nephrotoxic substances, and urinary obstruction. Symptoms vary widely, including sudden loss of appetite, weakness, convulsions, diarrhea, vomiting, polydipsia , polyuria, oliguria, and anuria.

・Chronic renal failure

It is a disease in which chronic lesions occur in the kidneys, resulting in a decline in kidney function.

Once kidney lesions have progressed, they cannot return to their original state, so early diagnosis of the disease and treatment to slow its progression are necessary. In the early stages, symptoms include excessive urination , weight loss, and decreased appetite.


Diabetes mellitus is characterized by high fasting blood sugar, polydipsia, polyuria , weight loss, and sugar in the urine. Diabetic ketoacidosis is a complication of diabetes that can be life-threatening if left untreated.


Alice's Dog & Cat_Veterinarian Column Pyometra

It occurs in unneutered cats and dogs. This is a disease in which a bacterial infection occurs in the uterus, causing pus to accumulate in the uterus. If there is no drainage from the vulva, the symptoms of poisoning may be severe and even life-threatening. Symptoms include loss of appetite, loss of energy, fever, polydipsia, polyuria , and vomiting.


There are various causes of hypercalcemia, such as lymphoma, chronic renal failure, and hypoadrenocortical insufficiency, but hypercalcemia causes symptoms of polyuria .

■Adrenocortical hypofunction

A lack of hormones secreted by the adrenal glands causes symptoms such as weakness, weight loss, loss of appetite, vomiting, diarrhea , excessive urination, bradycardia, hypothermia, and convulsions. Symptoms progress slowly, but the patient may suddenly go into shock.


It develops in conjunction with a urinary tract infection, resulting in polyuria and secondary polydipsia.


Hypokalemia occurs secondary to other diseases. Muscle weakness and excessive urination may be seen.


This disease often occurs in older cats. Symptoms include weight loss, excessive drinking , slight tachycardia, and gastrointestinal symptoms.

■Liver failure

When liver function declines due to various causes, symptoms may include polydipsia and polyuria .

■ Diabetes insipidus

Although it is a rare disease, symptoms are characterized by polydipsia and polyuria . Diabetes insipidus is caused by impaired hormone secretion from the pituitary gland, and diabetes insipidus is caused by impaired kidney function.

Excessive drinking and excessive urination are signs of illness. Some of these may be life-threatening emergencies, such as pyometra. Knowing the amount of water you drink and the amount of urine you drink (frequency and color) will help you detect diseases early.

If you feel that your dog is drinking a lot of water or is producing a lot of urine, bring the urine with you and consult a veterinarian.