The Differences Between Kidney Failure & Dehydration in Cats

Kidney failure causes your feline to pay way more visits to her litter box.
i BananaStock/BananaStock/Getty Images

Just like cats and dogs, dehydration and kidney failure in felines are two conditions that might share a few similarities, but they're mostly different from one another. From the short-term dangers of dehydration to the potentially long-term threats of kidney failure, the two conditions have contrasting symptoms, treatments and diagnoses.

Kidney Failure and its Causes

Picture a healthy feline's kidneys: they're going about their business, filtering waste and help her body to retain certain nutrients that go in. If your kitty suffers from kidney failure, her kidneys can't perform as efficiently. They're not filtering out enough waste and her urine begins consisting more and more of water rather than the waste products it normally is made up of. Kidney failure is a serious, life-threatening problem that comes in two flavors: acute kidney failure and chronic kidney failure. Acute kidney failure typically occurs because of a sudden incident, such as poisoning, bladder stones or even extreme dehydration. Caught quickly enough, the nasty problem can be fixed without further issues. But if it's left undiagnosed for too long, it can turn into chronic kidney failure. Chronic kidney failure can also be caused by conditions and medicines that typically happen or are administered over a longer period of time, such as a long-term infection of the kidneys, high blood pressure and long-term use of certain antibiotics.

Dehydration and its Causes

Dehydration happens when your kitty doesn't have enough water in her body. Whereas kidney failure can lead to death over time, dehydration can cause life-threatening symptoms within just a day if the condition is severe enough. But on the flip side, remedying dehydration, at least temporarily, is a whole lot easier than treating kidney failure, since it typically just requires a cool place and fluid intake. Causes of dehydration range from the simple, such as not providing enough fresh water for your kitty, to the complicated, such as kidney failure.

Dehydration Symptoms

Your kitty will appear lethargic as dehydration sets in, preferring to be a couch potato than do sprints through your hallways. Lift up her lips and press your finger gently onto her gums. Leave it there for a few seconds and then remove it. If a pink color returns within one to two seconds, she's not dehydrated. If her gums remain pale or white after removing your finger, she's dehydrated. As her dehydration worsens, she might pant and appear to walk with a drunken gait, as if she's confused about how to walk, falling over and stumbling into things.

Kidney Failure Symptoms

If your kitty is saddled with kidney failure, whether it's acute or chronic, you'll notice a handful of obvious symptoms that worsen as her kidneys gradually become less efficient. She'll start to drink more and may seem dehydrated. She'll eat less, play less and lay around more. She'll urinate more and you might notice she has trouble eliminating in her litter box and instead has accidents around the house. She might also cry out in pain when she relieves herself. Her urine may also look milky and cloudy, and as the condition starts hitting the life-threatening stages, you'll probably smell ammonia on her breath.


Kidney failure and dehydration are two conditions no kitty wants to have, but they're very different from one another. Dehydration is more life-threatening in the short-term, but it's almost always significantly easier to cure. Acute kidney failure can be cured, but chronic kidney failure is something that will stick with your kitty throughout her life, but there's always good news to combat the bad. Chronic kidney failure can be treated and somewhat managed, so it's not as if your kitty will be helpless.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

the nest