7 Possible Reasons Why Your Cat is Always Thirsty

Have you noticed a change in your cat’s drinking habits lately? Has she been drinking more water than usual? If you answered YES to both questions, read on! One of the reasons below might lead you to find out why your cat is always thirsty. 

As a reminder, this Waldo’s Friends blog post is only a guide. It is not meant to replace a visit to the veterinarian, but meant to arm you with information to help you become the best cat parent there is. If you notice your cat drinking excessively and displaying unusual behaviour (i.e. a change in appetite, sleeping more than usual, and peeing everywhere uncontrollably), schedule a trip to the vet ASAP.

This Waldo’s Friends post shares:

• How much water intake is considered normal in cats?
• Is there a medical term for excessive water drinking?
• What are the possible reasons your cat is so thirsty?
• What to do if your cat is excessively drinking water? 

How much water intake is considered normal in cats?

Vetwest Animal Hospitals states that a cat should drink an average of 60 ml per kg per day of water. So if your cat weighs 4 kg, she should be drinking approximately 240 ml a day to guarantee her body functions properly. 

Aside from her water intake, her diet should also be considered. If she eats wet food (which contains about 80% water), she only needs to drink about 30 ml of water per day. If she eats dry food (which contains about 10% water), she needs to drink more than 200 ml of water to make up for it.

Is there a medical term for excessive water drinking?

Yes, there is. The condition is called polydipsia. It is defined by Healthline as “the feeling of extreme thirstiness. Polydipsia is often linked to urinary conditions that cause you to urinate a lot. This can make your body feel a constant need to replace the fluids lost in urination. It can also be caused by physical processes that cause you to lose a lot of fluid. This can include sweating during exercise, eating a high-salt diet, or taking drugs that cause you to pass a lot of fluid, such as diuretics.” 

In cats, polydipsia is considered when a cat drinks more than 100 ml per kg of their bodyweight per day. Excessive drinking may be caused by one or more of the following factors: compensatory, pathological, behavioural, and environmental. Digestive issues or a change in diet may also lead to an increase in water intake. 

What are the possible reasons your cat is so thirsty?

1 Your cat could have a fever or infection.

Lamond Veterinary Clinic shares that infections or tumours may cause your cat to experience an increase in body temperature. This helps her fight the bug in her system, but at the same time, it also causes her to feel extra thirsty.  

2 Your cat may be stressed. 

Leslie Kuczynski, VMD, DACVIM of Metropolitan Veterinary Associates writes that excessive drinking could be a behavioural problem related to anxiety or stress. Examples of common cat stressors include moving homes, competing with other cats/pets, changing routines, and even having guests over.

3 Your cat could be dehydrated. 

Dehydration may be caused by overheating in warm places, dry or salty food (which may be caused by a sudden change in diet), and blood loss. 

4 Your cat may be suffering from diabetes mellitus.

Diabetes mellitus is characterized by high levels of sugar in the blood. The kidneys cannot reabsorb the glucose properly, so it overflows into the urine. The process is accompanied by large volumes of water, making your cat drink more to compensate for the loss. 

5 Your cat could have hyperthyroidism. 

When the thyroid glands produce excessive active thyroid hormones, this results in hyperthyroidism. It increases your cat’s metabolism, heart rate, and blood pressure—making the heart work faster and causing damage to the heart muscle. Hyperthyroidism also causes an increase in kidney filtration, which may cause dehydration.

6 Your cat may have chronic kidney disease. 

A more common affliction in older cats, this disease occurs when the kidney fails to function properly. One or both kidneys are unable to eliminate waste products effectively, balance electrolytes, produce certain hormones and vitamins, and/or maintain the body’s water balance. The kidneys are unable to reabsorb water, so excessive amounts are urinated. To make up for it, your cat drinks more. 

7 Your cat could be suffering from a urinary tract disease.

Excessive water drinking can sometimes be due to Feline Lower Urinary Tract Disease (FLUTD), which may make it difficult for her to pee. FLUTD may be caused by bladder stones, bacterial infection, urethral plugs, tumors, or anatomical defects.

What to do if your cat is excessively drinking water? 

Schedule a visit to the veterinarian immediately. Before your scheduled appointment, observe how much water your cat drinks for 24 hours and inform your vet about it. Fill her water bowls to the brim and measure the amount of water left after a day has passed. 

Also, ask your vet if you need to prepare a sample for a urine test. Collect a urine sample by following these steps from Vetwest Animal Hospitals:

1. Empty her litter tray. 
2. Clean it with soap and water. 
3. Place non-absorbable litter material such as Catrine crystals or a plastic bag cut into strips. 
4. After your cat pees, place the fresh urine in a clean glass jar.
5. Bring the urine sample to the clinic within an hour from collection. You can also place it in the fridge and take it to the clinic within 12 hours.

At the animal clinic, your veterinarian may run a complete physical exam to determine the underlying cause of your cat’s polydipsia. These may include running a complete blood count (CBC), a biochemical screen, a urinalysis, and a urine culture. 

In conclusion

Since cats are known for hiding their sicknesses, your cat’s excessive water intake may indicate an underlying illness at play. Early detection and suitable treatment of the illness work hand in hand in reducing your cat’s polydipsia. 

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