By Jennifer Copley (Last Updated 16 February 2011)
There are a number of illnesses that can trigger excessive thirst (polydipsia) and urination (polyuria) in cats.
Cats with polydipsia may drink from the shower, toilet, tub, sink faucets, or plant trays. Their litter boxes require scooping more often due to increased urination and their water bowls have to be refilled more frequently than in the past. Of course, many healthy cats drink from faucets and toilets, and normal water consumption and urination vary from one cat to the next. It’s changes in a cat’s habits that usually indicate a problem.
Illnesses That Cause Excessive Thirst and Increased Urination in Cats
The illnesses that most often trigger frequent urination and increased thirst in cats are:
- Kidney disease (also known as chronic renal failure or CRF)
- Diabetes mellitus
- Thyroid disease (hyperthyroidism)
These three diseases are common in older cats, and the latter two also cause increased appetite. Other illnesses and illness symptoms that can cause polydipsia and polyuria (some of which are quite rare) include the following.
Electrolyte abnormalities that can affect drinking and urination include:
- Low blood potassium (hypokalemia), typically resulting from symptoms of underlying illness, such as appetite loss, vomiting, or diarrhea
- High blood calcium (hypercalcemia), often due to a tumour, kidney disease, or other health problem
Endocrine (Hormonal) Disorders
Endocrine problems that can cause increased thirst and urination in cats include:
- Acromegaly, a condition whereby too much growth hormone is released into the system, often caused by a benign pituitary tumour
- Central diabetes insipidus, which may be triggered by head trauma, pituitary gland tumour, or unknown causes
- Hyperadrenocorticism (Cushing’s disease), usually caused by a benign pituitary tumour
- Hypoadrenocorticism (Addison’s disease), which can have a variety of different causes, the most common of which is autoimmune reaction (the body’s immune system attacking its own tissues)
Additional Causes of Increased Urination and Thirst in Cats
Miscellaneous triggers for polyuria and polydipsia in cats include:
- High red blood cell count (polycythemia), a symptom of many different illnesses
- Kidney infection (pyelonephritis)
- Liver disease
- Renal glycosuria, a kidney disorder caused by a disease or congenital defect
- Uterine infection (pyometra)
Treatment for polydipsia and polyuria varies based on the underlying cause.
Non-Illness-Related Causes of Increased Urination and Thirst in Cats
Non-illness-related polydipsia and polyuria triggers include:
- Administration of diuretics, salt, or certain medications
- Hot temperatures
- Increased exercise
- Post-obstructive diuresis (increased urination after removal of a urinary obstruction)
- Switch from wet food to dry (many cats on dry-food-only diets are chronically dehydrated)
Psychogenic polydipsia, an extremely rare obsessive-compulsive behavioural problem, can also cause excessive fluid consumption. Treatments for this condition may include behaviour modification therapy and gradual water restriction. In severe cases, a veterinarian may prescribe medications designed to reduce obsessive-compulsive behaviours.
Symptoms of Illness That May Accompany Polydipsia and Polyuria in Cats
Additional symptoms that suggest polydipsia and polyuria are due to a medical problem include:
- Behavioural changes
- Having accidents outside the litter box
- Increased appetite
- Loss of weight and/or appetite
- Poor coat condition
If you notice a change in your cat’s drinking or urination habits, consult a veterinarian.
For more cat articles, see the main Cats page.
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