Login Sign in
Login Sign in

Join thousands of pet parents and get vet-approved guidance, product reviews, exclusive deals, and more!

cat drinking water from faucet
Skip To


Severity: i Medium
Life stage: All
  • Water accounts for 60-70 percent of body weight in cats. Dehydration is a deficit of water.
  • Dehydration can quickly turn dangerous.
  • Symptoms include dry mouth, lack of appetite, elevated heart beat, muscle weakness, and more.
  • Causes include heat, limited access to water, diseases including kidney disease and diabetes, and medication.
  • If you suspect your cat is dehydrated, schedule a veterinary appointment.

If you’ve ever experienced dehydration, you know how awful it can be. Between the nausea, muscle cramps, and lethargy, it can quickly make you feel out of it. 

It turns out our cat can also experience similar side effects if they don’t stay on top of their hydration needs. 

We asked three veterinarians about the signs to look for, how dehydration in cats is treated, and how you can prevent it from happening to your favorite feline. 

What Is Dehydration?

“Dehydration is a deficit of water in the body,” says Dr. Stacie Summers, veterinarian and internal medicine specialist at Oregon State University’s Carlson College of Veterinary Medicine. “Water accounts for 60-70 percent of body weight in cats and is the main component of most body tissues.”

Summers explains that water in a cat’s body helps maintain normal blood flow to organs, transports nutrients, and eliminates harmful waste products through the kidneys. 

But dehydration in cats can mess with those important processes and quickly turn dangerous.

“Dehydration reduces blood flow and oxygen to vital organs, and causes serious electrolyte disturbances,” says Summers. “It also allows harmful waste products to accumulate in the body.”

It’s not easy to detect dehydration in cats, says Dr. Leah Cohn, veterinarian and small animal internal medicine specialist at the University of Missouri College of Veterinary Medicine.

“The lowest level of detectable dehydration is 5 percent, meaning the pet has lost 5 percent of body water. By the time the pet is 10 percent dehydrated, it is extremely ill,” she says. “Cats generally do not survive more than 12 percent dehydration without intensive care.”

Signs of Dehydration in Cats

Cat showing symptoms of dehydration in cats

There are a number of ways dehydration may present itself in your cat.

Dr. Summers says symptoms of dehydration in cats include:

  • Dry mouth
  • Poor skin elasticity (if you gently lift a cat’s skin and it takes longer to bounce back)
  • Hiding behavior
  • Poor appetite
  • Lethargy
  • Elevated heart rate
  • Muscle weakness (caused by electrolyte disturbances)

“With severe dehydration, brain swelling can occur,” adds Summers. “It can also cause kidney failure and shock from low blood pressure.”

What Causes Dehydration in Cats?

Cat drinking water from bowl

Healthy cats with access to clean water usually drink enough to maintain hydration. However, there are reasons that cats can become dehydrated. Some of these include:

Limited access to water. Cats that may not be able to access the water bowl could easily become dehydrated. Cohn explains that this might happen if water bowls aren’t refilled, if a cat is shut in a room away from the water, if a cat is kept away from the water bowl by another cat, or if a cat has limited mobility that makes getting to the water bowl difficult.  

Excessive heat. “This can cause dehydration, especially if the cat doesn’t have free access to water,” says Dr. Summers. When temperatures are high, pet parents should pay close attention and make sure their cats are drinking. 

Gastrointestinal fluid loss. “Frequent vomiting, regurgitation, or diarrhea can lead to loss of water,” says Cohn. 

Diseases or medical conditions. Cohn says that certain feline diseases may lead to more fluid loss through the kidneys than normal. “Two of the most common reasons for this would be kidney disease and diabetes,” she says.

Medications. Some medications for cats act as diuretics, which increase the amount of water and salt that leaves the body through urine. “Diuretics, like furosemide, are used to treat congestive heart failure,” says Dr. Summers.

Diagnosing Dehydration in Cats

If you suspect your cat is dehydrated, it’s important to make an appointment with your veterinarian. 

Your vet will perform a physical examination and laboratory testing, says Cohn, which may include blood tests that look at red blood cells and the proteins in the blood. Urine tests may also be performed to check its concentration.  

Dehydration Treatment for Cats

cat at the veterinarian being checked

Treatment may need to be done by your veterinarian, depending on the severity of your cat’s dehydration. 

“If there is more than mild dehydration, or if there is a medical reason that oral water will not correct dehydration (for example, your cat is vomiting and can’t keep water down), then intravenous fluids are required,” says Cohn. “If there is mild dehydration, administration of fluids under the skin may be adequate.”

Summers explains that fluids given under the skin are made up of a sterile electrolyte water solution that is given to your pet via a needle. “The water solution is then slowly absorbed into the body tissues and blood stream,” she says. 

Cat owners can also help treat very mild cases of dehydration at home, at the recommendation of a veterinarian.

“Unflavored electrolyte solutions like Pedialyte may be offered in moderation to cats under the direction of a veterinarian and only if the cat has free access to water,” says Summers.

Cost to Treat Dehydration in Cats

The cost to treat dehydration in cats is highly variable and depends on the severity and your location. For mild dehydration the first time you visit the veterinarian, the appointment will likely cost $150-$300, depending on the testing needed to determine why your cat was dehydrated in the first place and if any treatment besides hydration is required.

If your cat requires monthly fluid therapy for dehydration due to a chronic disease like kidney disease, “the cost of subcutaneous fluids ranges from $50-$100 per month,” says Summers. “To admit the cat to a hospital for intravenous fluids could range from $200 to over $1,000 depending on the severity of the hydration and how long it takes to correct the dehydration.”

How to Prevent Dehydration in Cats


Cat parents can help prevent dehydration by speaking to their veterinarian and making some simple lifestyle changes. 

Providing easy access to clean water is the most important thing that cat owners can do, says Cohn. “Some cats like flowing water, so the use of pet fountains encourages drinking in many cats,” she adds. Some automatic pet water fountains have different water flow modes (e.g., free-falling stream, bubbling fountain) to entice your cat to drink more.

Switching cats to a wet-food diet or incorporating wet food into a cat’s diet may also provide additional moisture and help prevent dehydration. “Wet cat food contains about 70 percent moisture and dry cat food contains about 10 percent moisture.”

If you don’t want to splurge on wet cat food, Summers says that you can add water to dry cat food to help them with hydration. “However, this may deter some cats from eating the food, so a gradual addition of water may be necessary,” she says. 

Before trying anything at home, just make sure to consult your vet.

“Prior to implementing any household or dietary changes, cat owners should consult with their veterinarians about the specific needs for their cat,” says Summers.