Dehydration in Cats

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

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 Dr. Summers. “It can also cause kidney failure and shock from low blood pressure.”

A dehydrated cat may urinate more or less than normal depending on the underlying cause of their dehydration. For example, a cat with kidney disease is likely to urinate more and might be dehydrated despite an increase in water intake. A cat who is dehydrated due to a simple lack of water access is more likely to urinate less (and more concentrated).

What Causes Dehydration in Cats?

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 Dr. Cohn. 

Diseases or medical conditions. Dr. 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. Hyperthyroidism is another common feline condition that can lead to dehydration.

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. Dehydration results if the cat doesn’t drink enough to make up for water loss.

Diagnosing Dehydration in Cats

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

Veterinarians can diagnose dehydration with a physical exam but will perform additional laboratory testing to determine the underlying cause of dehydration. This 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

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 Dr. 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 Dr. 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 Dr. 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.”

Your veterinarian may be willing to teach you how to administer subcutaneous fluids at home, which may help reduce costs.

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 Dr. 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, Dr. 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 Dr. Summers.

Ensure your pet gets annual wellness exams, including routine blood testing, so that health conditions that may lead to dehydration can be caught early.