Cats are masters of disguise. In the wild, showing weakness makes you a target, so our domestic house cats have retained the impressive ability to hide when they aren't feeling well.
This stoicism makes it incredibly challenging for pet parents to spot health issues early. One of the most common (and dangerous) issues is dehydration.
We spoke with Dr. Ambika Vaid, Integrative Veterinarian and Advisor to Badlands Ranch, to understand exactly what signs to look for and how to check your cat at home.
Why are cats so prone to dehydration?
You might assume your cat is fine because they have a water bowl, but their diet plays a massive role.
"Most cats are being fed a kibble diet because it’s easy and convenient," says Dr. Vaid. However, "Cats were not designed to consume kibble, which is highly processed and adds a drying component to their diets."
Because cats are obligate carnivores, they thrive on moisture-rich protein. When they rely solely on dry food, they often don't drink enough water to make up for it. Dr. Vaid warns that chronic dehydration "can lead to kidney damage as well as long-term kidney disease." It can also cause urine to become too concentrated, leading to painful crystals or stones.
The Two Best At-Home Tests
Because cats are so good at hiding illness, you need to know how to perform a physical check. Dr. Vaid recommends two specific tests you can do right now.
1. The "Skin Tent" Test
This is the most reliable way to check hydration levels.
- How to do it: "Using the loose skin between the shoulder blades, use your index finger and thumb to grab that loose skin and raise it about 1-2 inches," explains Dr. Vaid. "Once you’ve made a 'tent' with the skin, release your fingers."
- What to look for: In a hydrated cat, the skin is elastic and should snap back immediately. "If it takes a little longer or does not go all the way back to its original state, this is already a sign of at least 5% dehydration."
2. The Gum Check
Your cat’s mouth offers major clues about their hydration status.
- How to do it: "Lift your cat’s upper lip and gently press on the gum," instructs Dr. Vaid.
- What to look for: You want the gums to be nice and moist. "If it is dry or tacky, that is an early sign of dehydration." If the gums are pale, sticky, and dry, Dr. Vaid warns that this is a sign of "severe dehydration."
Other Signs to Watch For
Beyond the physical tests, keep an eye out for these changes in behavior and appearance.
- Lethargy: Dehydration reduces blood volume and oxygen to the muscles, leading to fatigue. If your cat has "lower energy" or is sleeping more than usual, take note.
- Litter box changes: Dr. Vaid notes that "very concentrated urine is an early sign of dehydration." If you notice the clumps are smaller or the urine smells stronger than usual, they likely need more fluids.
- Sunken eyes: If the eyes appear dull or sunken into the sockets, the body is conserving water by shrinking the tissues around the eyes. This is a serious symptom.
- Loss of appetite: Dehydration messes with digestion. If your cat is refusing to eat, nausea from dehydration could be the cause.
When is it an emergency?
If you suspect dehydration, do you rush to the ER or try to fix it at home?
"If your cat is otherwise acting normally at home, such as still being playful, eating and drinking, [and] using the bathroom okay, then you can try to wait and see," says Dr. Vaid. Focus on getting them to drink (tips below!).
If dehydration is accompanied by other symptoms, don't wait. "If your pet is also not eating, vomiting, having diarrhea, or lethargic/reluctant to move, I would recommend going to the ER immediately," advises Dr. Vaid. At this stage, "oral fluid intake will not be enough to help your pet," and they may need IV fluids.
How to Encourage Your Cat to Drink
If your cat is a "reluctant drinker," you need to make hydration appealing.
- Switch up their diet: Dr. Vaid suggests adding "one meal of canned food to their diet," which is typically 70-80% moisture. You can also add water or low-sodium broth to their dry food to hydrate them while they eat.
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Use a water fountain: This is the game-changer. "Cats also love water fountains, so purchasing one of these will really entice your pet to drink more water," says Dr. Vaid.
The Most Important Takeaway
If you remember only one thing, it’s that dehydration is a leading cause of long-term health issues for cats. Dr. Vaid emphasizes that because dry kibble adds a "drying component" to their diet, we have to actively help them get enough moisture.
You don't need to overhaul their entire life overnight. Small changes, like swapping one meal to wet food or setting up a Penthouse Paws Smart Water Fountain to make drinking fun, can effectively protect their kidneys and keep them healthy for years to come.