Increased thirst (polydipsia) in cats

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026
Table of contents

When to visit the vet?

Urgent see a veterinarian within 24 hours

?

RED if accompanied by apathy, vomiting, shortness of breath, neurological signs, or very severe dehydration.

Unsure about what’s wrong with your pet? Feel free to use our Symptom Checker for more clarity

Definition

Increased thirst, also known as polydipsia, is a condition in which a cat consumes significantly more water than normal. This can be an indication of various health problems and should be closely monitored.

Can Occur with the Following Diseases:

Basics and possible causes

Polydipsia often occurs in response to increased water excretion in the body, which can be caused by various diseases. Normally, cats regulate their water needs very precisely, and a deviation from this is often a sign of an underlying problem.

One of the most common causes of increased thirst in cats is renal failure. The kidneys play a crucial role in fluid regulation, and if they do not function properly, this can lead to increased thirst. Chronic kidney diseases are common, especially in older cats.

Diabetes mellitus is another disease that can lead to polydipsia. In diabetes, the cat’s blood sugar level is elevated, which overloads the kidneys and leads to increased fluid loss through urine, requiring the cat to drink more to compensate for this loss.

Hyperthyroidism, an overactive thyroid gland, can also lead to increased thirst. This hormonal disorder accelerates the cat’s metabolism, which can lead to increased fluid excretion and thus increased thirst.

Other possible causes include liver diseases, certain medications, especially diuretics, and infections such as pyometra, a uterine infection in unspayed female cats.

Typical accompanying symptoms

  • Increased urination: Cats with polydipsia often also show polyuria, meaning they excrete more urine than normal, which often accompanies increased water intake.

  • Weight loss: Weight loss can occur with some underlying conditions, such as diabetes or hyperthyroidism, even if the cat eats normally or more than usual.

  • Changes in appetite: An increased or decreased appetite can also be an accompanying symptom, especially in metabolic diseases such as diabetes and hyperthyroidism.

  • Vomiting and Diarrhea: These symptoms can occur in renal failure or other systemic diseases and lead to further dehydration.

  • Weakness and lethargy: These symptoms often occur in advanced diseases and may indicate a serious impairment.

  • Changes in coat: A dull or unkempt coat can indicate a chronic illness that is also associated with polydipsia.

  • Behavioral changes: Some cats show Behavioral changes such as increased meowing or Restlessness, especially when they feel unwell.

When to see a vet?

A visit to the veterinarian is essential if the cat drinks significantly more than usual for more than a few days. This is particularly important if, in addition to increased drinking habits, the cat shows other symptoms such as weight loss, vomiting, diarrhea, or changes in behavior.

If the cat appears lethargic or shows signs of Fluid loss (dehydration), such as dry mucous membranes or sunken eyes, immediate veterinary attention should be sought.

Even if the cat is older, it is important to perform regular health checks, as older cats are more susceptible to diseases such as renal failure and diabetes, which can cause polydipsia.

Symptom recognition for the pet owner and veterinary diagnostic procedure

Pet owners should monitor their cat’s water intake. One way to do this is to measure the amount of water filled into the bowl and the amount remaining after 24 hours. This helps collect objective data that can assist the veterinarian.

The veterinarian will likely perform a thorough clinical examination to identify other symptoms or signs of disease. Blood tests are often the next step, as they can provide important information about kidney function, blood sugar levels, and other relevant parameters.

A urinalysis can help determine the concentration of urine, which can provide clues about kidney problems or diabetes. In some cases, X-rays or ultrasound examinations may also be necessary to rule out structural abnormalities or tumors.

The veterinarian will use the collected data to make a diagnosis and develop a therapy plan. It is important to follow all suggested tests and treatments to improve the cat’s health.

What the pet owner can do and professional therapy options

The pet owner should ensure that the cat always has access to fresh, clean water. This is especially important if the cat shows polydipsia, as it may be trying to compensate for increased fluid loss.

It is advisable to monitor the cat’s eating habits and adjust them if necessary. Special diets may be required, especially if polydipsia is caused by an underlying condition such as renal failure or diabetes.

Stress can worsen health problems in cats, so the owner should ensure that the cat’s environment is calm and stress-free. Toys, hiding places, and regular interaction can help reduce stress.

For confirmed diseases such as diabetes, it is important to follow the veterinarian’s therapy plan precisely, including administering medication or insulin if required. Regular check-ups with the veterinarian are also crucial to monitor the cat’s condition and make adjustments to the therapy plan.

Outlook on current research

Research on polydipsia in cats focuses on understanding the underlying mechanisms that cause this increased thirst. There are currently several hypotheses being investigated. One theory suggests that hormonal imbalances, particularly related to antidiuretic hormone (ADH), could play a role. Studies have shown that changes in the regulation of this hormone can affect both thirst and urine production, leading to increased water intake.

Another area of research investigates the role of kidney function in the development of polydipsia. The kidneys are crucial for regulating the body’s water balance, and an impairment of their function can lead to increased thirst. Current studies use advanced imaging techniques to analyze kidney structure and function in cats with polydipsia to identify possible anomalies or deviations.

Genetic predisposition is another topic that is gaining increasing importance in research. Scientists are investigating whether certain breeds or genetic lines are more susceptible to polydipsia than others. Genetic studies could provide clues as to which genes are involved in regulating thirst sensation and how variations in these genes can influence the risk of developing polydipsia.

The role of nutrition is also being highlighted in current research. It is being investigated how different food compositions, especially salt content, can influence the drinking behavior of cats. Some studies suggest that a high-salt diet increases thirst, as the body tries to compensate for the salt through increased fluid intake. Future research could lead to specific dietary guidelines to manage or prevent polydipsia.

Another relevant aspect of research is the environment. Research has shown that environmental factors such as temperature and humidity can influence drinking behavior. In warmer climates or in households with central heating, a cat’s water requirement may increase to compensate for fluid loss through sweating or evaporation. These findings could help improve the diagnosis and therapy of polydipsia by considering the role of environmental factors in the detection and management of the symptom.

There are also research efforts focusing on the development of new diagnostic tools. These tools could enable veterinarians to quantify polydipsia more accurately and distinguish it from normal fluctuations in drinking behavior. Advances in diagnosis technology, such as portable monitoring devices that can track a cat’s water consumption in real-time, could revolutionize the diagnosis and management of polydipsia.

Future research will likely also focus on developing interventions to better treat or control polydipsia. This could include researching medications that target underlying causes, such as hormonal or neurological anomalies, as well as developing special diets or supplements that can naturally regulate thirst.

In summary, research on polydipsia in cats is a dynamic and growing field that will continue to provide new insights into the biological, genetic, and environmental factors influencing this condition. This research has the potential not only to deepen the understanding of polydipsia but also to significantly improve the quality of life for cats affected by this symptom.

Frequently asked questions

1. What is polydipsia in cats?
Polydipsia refers to abnormally increased thirst and water intake in cats. It is a symptom that can indicate various underlying health problems.
2. How much water should a healthy cat drink?
A healthy cat should generally drink about 50-70 ml of water per kilogram of body weight per day. Deviations from this can indicate polydipsia.
3. What signs indicate that my cat is drinking too much?
If your cat visits the water bowl more often than usual or drinks unusually large amounts of water at once, this could indicate polydipsia.
4. Could increased water intake be normal for my cat?
In some cases, such as warm weather or a high-salt diet, increased water intake may be normal. However, if there is no obvious cause, this should be checked by a veterinarian.
5. What health problems can cause polydipsia?
Polydipsia can be caused by a variety of health problems, including kidney diseases, diabetes mellitus, hyperthyroidism, and Cushing's syndrome.
6. How is polydipsia diagnosed in cats?
Diagnosis requires a thorough medical history, a physical examination, and possibly blood and urine tests to identify the underlying cause.
7. Can stress cause polydipsia in cats?
Stress can indirectly lead to increased water intake by exacerbating other health conditions that cause polydipsia, such as diabetes or hyperthyroidism.
8. Can polydipsia be treated in cats?
The treatment depends on the underlying cause. Once the underlying disease is diagnosed and treated, the symptom of polydipsia can also improve.
9. What can I do to monitor my cat's water intake?
You can monitor water intake by measuring the amount of water put into the bowl and checking the remaining amount after 24 hours. Automatic water dispensers with counters can also be helpful.
10. When should I see a veterinarian if my cat drinks a lot?
If your cat suddenly drinks more without an obvious cause such as hot weather, or if it shows other symptoms such as Weight loss or changes in appetite, you should see a veterinarian.