Why Is Your Cat Drinking a Lot of Water?

If it is about being dehydrated, it is important to consider the reason why. Most cats will wait until they are very dehydrated before they drink water.

The reasons for dehydration could be as simple as eating dry food, playing hard, or being stressed. Sudden increased thirst is very concerning and can be caused by many serious medical conditions. If your cat is suddenly drinking a lot of water, it is time for a visit to the veterinarian.

Cats and Water in the Wild

It is a rare sight to see cats drink water when they live “in the wild.” They are adapted to live in very dry climates and get most of the moisture they need from the prey they hunt.

This is actually a health benefit because it avoids getting bacteria and parasites from water. If cats do drink water, they prefer running water which is another way to help avoid diseases.

Cats can be reluctant to drink water, even in our homes. While a dog will drink an entire bowl in a few seconds, cats would never dare to be so greedy. A dog can recover from dehydration in under four hours, while a cat will take a full day to do so.

Lack Of Water In Food

The first thing to consider is whether cats are getting enough water on their own. Some cats do not drink a lot of water from their water bowl and therefore, get most of their water intake from their food like their wild counterparts.

The biggest reason most owners see their cats drink water at all is a dry food diet because they have no other choice. Kittens especially will drink a lot of water when fed dry food.

If you mostly feed your cats with dry foods, you have recently changed from wet food to dry food or even changed the quantity of food you feed your cat, then this might be the culprit for their increased drinking habits.

Dry cat foods only contain about 5% to 10% of water moisture. This is not enough to fill your cat’s daily water needs.

Regardless of how much your cat drinks, it is unlikely that they will drink enough to compensate for a dry diet. This leads to chronic dehydration which can lead to numerous other issues.

Wet cat foods, on the other hand, usually have 70% to 80% water moisture. They will not provide all the water your cat needs either but will provide a good amount.

Aside from these differences in moisture content, both wet and dry cat foods are nutritionally complete.

If you see your cat drinking a lot, you can help it out by adding wet food to its diet.

Wet cat food in a bowl

Dry Food Versus Wet Food

An average cat needs about 20 teaspoons of water a day. Each tongue-lap from the water bowl only collects 3/100ths of a teaspoon which is not a very efficient way to get water.

A ten-pound adult cat eating only dry food needs to drink an extra cup (250ml) of water, whereas a cat eating only wet food needs to drink a third of a cup (75ml) of water a day.

There are definitely pros and cons to both types of food. While wet cat food ensures that the cat is getting more moisture, dry cat food is helpful in preventing dental disease by about 10 percent (compared to wet food)(Source). Dry food is also less expensive and less messy and can be left all day in the food bowl.

If you are unsure what sort of cat food your cat should be eating, your veterinarian will be happy to aid you in choosing a high-quality food.

More moisture content is not the sole reason to change from dry food to wet food. There is nothing wrong with your cat drinking plenty of water from the water bowl to make up for its fluid needs if they are on dry food.

Increase in Thirst Due to Diseases

Excessive drinking is also a possible symptom of an underlying disease. A sudden or steady increase in thirst is an important sign that something is wrong.

Make an appointment with your veterinarian. Until your vet appointment, help keep your cat hydrated by continuing to offer clean water in several locations in your home.

The following are some possible medical causes of increased thirst:

  • Diabetes

Humans aren’t the only species that can suffer from diabetes as cats are also susceptible to it. Diabetes in cats can either be Type I (in which the body stops producing insulin), or Type II (insulin is present but its effectiveness is suppressed).

The pancreas produces insulin which regulates blood sugar levels. But when the blood sugar levels rise due to a lack of insulin, your cat might experience some worrying symptoms.

Overweight cats are especially prone to diabetes. Out of control blood sugar will cause the kidneys to work overtime in an attempt to remove the sugar. This increases urination which in turn increases thirst.

Other things that might be seen with this disease include a change in appetite (initially increased, followed by decreased), sudden weight loss, and lethargy. If it is advanced, your cat could start experiencing seizures or even go into a coma.

Your veterinarian will test your cat’s blood glucose to determine if diabetes is the cause of their increased thirst. Feline diabetes is best managed by weight loss and twice-daily insulin injections.

  • Kidney Disease

Your cat’s kidneys might be deteriorating; which could be the reason for its excessive drinking.

Kidney disease also causes increased urination. The diseased kidneys are less efficient, so they need more water to do their job.

Other than increased drinking, symptoms to look for are decreased appetite, weight loss, vomiting, bloody or pale urine, and weakness. Kidney disease is common in older cats, especially if they have been on a dry diet for most of their lives.

Although this is the case, don’t be complacent as this can happen to cats of any age.

Unfortunately, there is no cure for kidney disease, but catching it early can help slow the progress of the disease. However, once the kidneys are damaged, it cannot be reversed.

Kidney disease can be easily diagnosed with a blood or urine test by your vet and timely action early in the course of the disease will slow the progression. The vet will test your cat’s blood to see how well the kidneys are working and there are many different medications to help control kidney disease.

Keep in mind that by the time your cat is showing symptoms, its kidney disease is already in advanced stages. Regular checkups with blood work can detect kidney disease early and greatly help your cat.

  • Hyperthyroidism

Cats that eat a lot yet remain thin often have hyperthyroidism. This typically only occurs in cats over ten years old. The increased appetite often leads to increased thirst as well.

It is unknown why some cats get this and some don’t, but it is very common especially in aging cats. The thyroid controls the metabolism of the body.

Apart from increased drinking, symptoms include weight loss, increased urination, prolonged staring, hyperactivity, increased heart rate, panting, a goiter (or lump) in the neck, and vomiting. It usually occurs in middle-aged or older cats.

If your veterinarian suspects hyperthyroidism, they will check the blood to see if the thyroid hormone levels are within the correct range. The condition can be managed with medication and/or a prescription diet and cats with hyperthyroidism can still go on to live long and happy lives.

There are also options for surgery or radioactive iodine treatment to control the thyroid gland.

  • Liver Disease

Liver disease may also cause increased thirst and urination. Similar to kidney disease, your veterinarian will do a blood test to diagnose liver disease. There are many kinds of liver disease – some acute and some chronic.

It would be extremely rare for increased water consumption to be the only sign of liver disease. Other signs include vomiting, inappetence, fever, and lethargy. In severe cases, your cat may require hospitalization.

  • Vomiting and Diarrhea

Cats can vomit or have diarrhea for a number of reasons. Vomiting, and especially diarrhea can lead to water loss and dehydration. If serious enough, your cat may need to receive fluids to recover from dehydration.

Once the underlying cause of vomiting or diarrhea is taken care of, your cat should no longer be at risk of dehydration. In kittens, the cause is usually a parasite or infection. For all cats, household toxins including houseplants, obstructions, or organ failure are some other possible causes.

  • Medications

Certain medications, most commonly steroids, will cause increased thirst and urination. A small increase is normal, but if it seems excessive, call your veterinarian.

Your cat may need to have their medication adjusted. Do not simply stop the medication as many need to be slowly tapered off.

How to See if Your Cat is Drinking Too Much Water?

Okay, maybe you’re noticing that your cat is drinking more often than usual. Perhaps it’s not really drinking much. How can you figure out your cat’s water intake?

Before heading to the vet, it’s always a good idea to observe your cat carefully. Cats typically drink between three and five ounces of water (¼ to ½ of a regular glass) per five pounds of body weight per 24 hours. This can be different depending on their diet.

To see if your cat is really drinking too much, measure the amount of water you’re giving them. Do this by filling up the water bowl with a specific amount of water in the morning.

Then, 24 hours later, measure the remaining water. This way you can work out how much has been consumed within that time period.

How to Keep Kitty Hydrated

No matter the cause, it is a good idea to help keep a thirsty cat hydrated. In addition to treating any underlying medical conditions, there are many ways to help keep your cat hydrated.

Feeding wet food is the first step an owner should take. Wet food will make the largest impact on your cat’s total water consumption.

Some cats that have eaten dry food their whole lives are resistant to eating wet food. It may take some effort on your part to make the switch, but it will be of huge benefit.

Pet drinking fountains can also help attract your cat to drink the flowing water.

Some cats can be particular about the location or the flavor of their water. Experiment with water dish locations throughout the home. You can also try bottled water if you suspect your tap water doesn’t taste the best.

In cases of severe vomiting or diarrhea or in cases of kidney disease your cat may need to receive subcutaneous fluids. This is a relatively easy process where excess fluid is placed just under your cat’s skin using a needle and an IV bag. These fluids will not only provide water but also help maintain electrolyte balance.

Problems Caused by Dehydration

You may notice that you simply feel better when you remember to keep hydrated. Cats are no different. Well-hydrated cats have more energy and have less strain on their kidneys.

Serious medical issues are also caused by chronic dehydration. This kind of dehydration typically comes from feeding a completely dry diet. Your cat may drink a lot, but again, cats simply don’t have the urge to drink enough to stay their healthiest.

Urinary tract infections, bladder stones, and kidney disease are all partially caused by dehydration. At best, a urinary tract infection is a painful inconvenience for your cat. At worst, a urinary stone can cause a deadly blockage requiring emergency surgery.

Jaimee Alsing, an animal nutritionist, holds a BS in Animal Science from Cornell University, where she focused her coursework heavily on animal nutrition. She founded a small award-winning company, Colorado Care Co., which formulated and produced all-natural hermit crab and reptile food.

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