Kidney disease is one of the most common health concerns in cats, especially as they age. But what makes it particularly challenging is how quietly it can develop. The good news is that recognizing the early signs of kidney disease in cats can make a huge difference.
As Dr. Dody, one of our resident veterinarians, says, “When you give the right support – and you give it early - cats with kidney disease can have a good quality of life for years.”
NOTE: In this article we are discussing chronic kidney disease, which worsens gradually over months or even years. Acute kidney disease shares many of these symptoms but occurs suddenly and is a medical emergency.
What do your cat’s kidneys do?
Your cat’s kidneys have several critical functions to play in your cat’s body. These include filtering waste products from the bloodstream, regulating hydration, supporting a proper electrolyte balance, and helping manage blood pressure.
Dr. Dody explained, “The kidneys are constantly working behind the scenes. When they begin to lose function, the effects start showing up throughout the body as many different changes and symptoms.”
Because the kidneys are involved in so many essential processes, even small changes in function can lead to noticeable shifts in your cat’s health or behavior over time.
How common is kidney disease in cats?
Kidney disease affects as many as 40% of cats by the time they’re 10 years old. That percentage increases to 80% when they reach 15.
“Because kidney disease is so common, and so intrinsically linked with aging,” Dr. Dody said, “I recommend all pet parents watch for signs of kidney disease in their aging cats while also having their vet regularly monitor them for this disease.”
Why kidney disease is common in cats
There are several reasons why kidney disease appears so often in cats. Cats have a low thirst drive, meaning they tend to drink less water. This puts more stress on the kidneys over time.
Due to medical advances, cats live longer now than they did in the past. Living longer gives cats more time to develop age-related conditions like kidney disease. Some cats have genetic issues or other medical conditions that put strain on the kidneys.
Many times, there is no discernible cause besides age.
Early signs of kidney disease in cats
“The early signs of kidney disease in cats develop gradually and can be easy to miss,” Dr Dody said. “You may see just a few of them, or all of them. The important thing is to be aware of the signs and not to dismiss them out of hand.”
1. Increased thirst and urination
One of the earliest and most common signs is increased thirst, which leads to increased urination. You may notice your cat visiting the water bowl more often. When you check the litter box, you may notice the clumps are larger or that there are more of them.
2. Weight loss
Weight loss and/or muscle loss usually happens slowly and may not involve changes in appetite at first. You may notice them having trouble making jumps they used to handle easily, or maybe they just feel smaller or lighter in your arms.
3. Lower energy or changes in behavior
Your cat may start sleeping more, playing less, or just seem less engaged with the people and things around them. These changes are often mistaken for normal aging.
4. Changes in appetite
Some cats begin eating less, while others may become more selective about their food. Appetite fluctuations are common in early kidney disease.
5. Digestive upset
Occasional vomiting or nausea may occur as waste products begin to build up in your cat’s body.
6. Bad breath or oral changes
You may notice a change in your cat’s breath, sometimes described as having an ammonia-like odor.
7. Coat and grooming changes
A cat that once had a sleek, well-groomed coat may begin to look dull or unkempt. This can be a sign they’re not feeling well enough to maintain their normal grooming habits.
Why early detection matters
Many of the early signs of kidney disease in cats can be mistaken for normal aging, but they should not be ignored. Early intervention matters for a cat’s life expectancy as well as their quality of life.
Cats have a remarkable ability to compensate for declining kidney function. In fact, symptoms often don’t become obvious until a significant portion of kidney function has already been lost.
That’s why paying attention to subtle changes and taking your cat for regular vet checkups are both so important.
“We don’t always get dramatic warning signs early on,” Dr. Dody said, “but small, consistent changes in behavior, appetite, or hydration can be the first clues. Catching those early gives us more options to support the cat.”
What to do if you notice signs of kidney disease in your cat
If you notice any of these changes, even if they seem mild, take them seriously.
Reach out to your veterinarian.
You know your cat best. You know if something has changed. And changes deserve attention.
How kidney disease is diagnosed
Kidney disease cannot be diagnosed based on symptoms alone. Your veterinarian will typically use a combination of bloodwork and urine testing, though sometimes imaging is used as well.
These tests help assess how well the kidneys are functioning and guide the treatment plan.
Common medical treatments for kidney disease
Treatment will depend on the stage and severity of the condition and may include:
- fluid therapy to support hydration
- medications to manage nausea or blood pressure
- prescription kidney diets
- phosphorus binders to remove phosphorus through the digestive system instead of the kidneys
Dr. Dody added, “Unfortunately, there is currently no cure for kidney disease. However, treatment can slow the progression of the disease and greatly improve your cat’s quality of life.”
Supporting your cat early through lifestyle and nutrition
While medical care is essential for cats with kidney disease, daily lifestyle and nutrition choices also play a major role in supporting kidney health. This is especially true before your cat shows noticeable signs of kidney disease.
“I always recommend for pet parents to support their cat’s kidneys long before any symptoms appear,” Dr. Dody said. “By providing early support, you keep your cat’s kidneys healthy longer and give them the best chance at a long and healthy life.”
Her recommendations are:
1. Hydration support
Because hydration is so important for kidney function, supporting adequate water intake is one of the best things you can do for your cat’s kidney health.
This may include:
- feeding moisture-rich foods
- providing multiple fresh water sources
- using cat water fountains to encourage drinking
2. Nutritional support
Nutrition is a cornerstone of kidney support.
Dr. Dody notes, “People often think that a ‘kidney-friendly’ cat diet means removing protein, but nutrition isn’t just about what we remove. It’s about what we provide.
“A well-balanced, moisture-rich diet that’s tailored to older cats can help reduce the workload on your cat’s kidneys while giving them the protein they need to maintain muscle as well as the calories and nutrients to provide energy and promote overall wellbeing.
“That being said, there are nutrients that I recommend adjusting, like shifting to a moderate phosphorus cat food as a cat gets older. This can benefit many senior cats, as it reduces strain on aging kidneys.
“Homemade cat foods made that are designed by vets specifically for senior cats are great for providing age-appropriate nutrition without putting extra strain on their kidneys.
“Now if your cat has a blood test or urine test that suggests their kidney function has already declined a bit, veterinary kidney specialists recommend immediately transitioning to a low phosphorus cat food. By reducing dietary phosphorus at the first hint of trouble, you can slow the progression of kidney disease.
“Of course, if your cat has progressed to the point where a prescription kidney diet is recommended as part of their treatment plan, follow your vet’s directions.”
Conclusion
The early signs of kidney disease in cats can be easy to miss. But those small changes—drinking a bit more water, eating a little less, sleeping more than usual—can be important signals and should never be ignored. Through early detection and proper treatment, you can delay kidney disease’s progression and give your cat more years and a better quality of life.
Frequently Asked Questions About the Signs of Kidney Disease in Cats
What are the first signs of kidney disease in cats?
The earliest signs of kidney disease in cats are often subtle and may include increased thirst, increased urination, weight loss, lower energy levels, appetite changes, vomiting, or changes in coat quality.
At what age do cats commonly develop kidney disease?
Kidney disease becomes much more common as cats age, especially after age 10. However, some cats may develop kidney issues earlier due to genetics, underlying medical conditions, or other factors.
Can kidney disease in cats be cured?
Chronic kidney disease cannot currently be cured, but early detection and proper treatment can slow disease progression and greatly improve your cat’s quality of life.
How do veterinarians test for kidney disease in cats?
Veterinarians typically diagnose kidney disease using bloodwork and urine testing. These tests help evaluate kidney function and identify changes before symptoms become severe.
Does drinking more water always mean a cat has kidney disease?
Not always. Increased thirst can have several causes, including diabetes or hyperthyroidism. If you notice your cat drinking more water than usual, it’s important to have them evaluated by a veterinarian to determine the cause.
Can diet help support cats with kidney disease?
Yes. Nutrition plays a major role in kidney support. Moisture-rich foods, proper hydration, and appropriate phosphorus levels may help reduce stress on your cat’s kidneys and support their overall health. If your cat has later stage kidney disease, your vet may prescribe a prescription kidney food for your cat.