Why Older Cats Act 'Different' — It's Not Just Age
When your older cat acts differently, do not assume it is simply old age. Their behaviors are signals — sometimes whispers, sometimes cries — that something is changing inside.
Reviewed by Dr. Tracy Duffner
Join the Bark & Whiskers™ Family
Sign up today for our FREE newsletter, packed with expert advice and insider tips to keep your beloved pet in tip-top shape.
View our Privacy Policy and Terms of Service.
STORY AT-A-GLANCE
- Many behavior changes in older cats are not simply aging — they are often signs of underlying disease, making early recognition and veterinary care essential for comfort and health
- Common conditions in senior cats include arthritis, kidney disease, hyperthyroidism, and dementia, each altering behavior in ways owners often mistake for quirks or natural aging
- Arthritis makes jumping, grooming, and litter box usage difficult, while kidney disease and thyroid problems can trigger weight loss, thirst, restlessness, and loud nighttime vocalizations
- Feline dementia affects memory, sleep cycles, and interactions, leaving many cats disoriented, anxious, or vocal, yet these symptoms are often dismissed as "just getting old"
- Small changes at home — like ramps, low-sided litter boxes, night lights, fountains, and consistent routines — combined with regular veterinary visits, can greatly improve a senior cat's quality of life
Cats are full of mystery. They slip through our lives with quiet grace, often revealing only what they choose. For centuries, people have admired them for their independence, elegance, and stubborn self-sufficiency. But when your beloved companion enters their senior years, that mystery can become a puzzle.
Maybe your cat used to race through the house at midnight but now sleeps nearly all day. Maybe they have started calling out in the dark, staring at walls, or refusing to use the litter box. Perhaps they have grown clingier, following you from room to room, or suddenly crankier, swatting at gentle touches. It is tempting to shrug and say, "Well, she's just old."
But new veterinary research tells us otherwise. Most behavioral changes in older cats are not simply the result of aging — they are signs of underlying disease.1
That means your cat's new habits could be a cry for help. And the earlier you listen, the better chance you have of easing discomfort, slowing disease, and giving them more happy years by your side.
Aging vs. Illness — What's the Difference?
Just like people, cats undergo natural changes as they grow older. Their bodies slow down, their senses dull, and their organs gradually lose efficiency.2
A healthy 15-year-old cat may not leap onto counters the way they did at age 5, and that is normal. But here is the catch — age itself does not explain dramatic changes.
Aging is not a disease. Veterinarians point out that distinguishing between "normal aging" and illness can be tricky. For example:3
- A little extra napping is normal. Sleeping almost all day, refusing to move, or hiding in unusual places could mean pain or kidney disease.
- Senior cats groom themselves less; however, a significant decrease in grooming or stopping grooming altogether may suggest arthritis or dental disease.
- A quieter personality may fit with age. But sudden withdrawal, confusion, or nighttime yowling points to something more.
The key message is this — behavior changes matter. In a large survey, more than 60% of cat owners reported noticing behavioral changes in their older cats, most of which were tied to medical problems.4
4 Diseases That Alter Behavior in Senior Cats
One of the largest studies of senior cats showed that over half of cats older than 9 years had at least one disease diagnosed.5 The most common were:
- Osteoarthritis (OA) — Chronic joint or spinal pain.
- Chronic kidney disease (CKD), which gradually leads to kidney failure.
- Hyperthyroidism — Having an overactive thyroid gland.
- Cognitive dysfunction syndrome (CDS) — Feline dementia.
These conditions do not just cause physical symptoms — they reshape how cats eat, sleep, interact, and even express affection.
Osteoarthritis — The Silent Thief of Mobility
When you think of arthritis, you probably imagine limping or stiff joints. Cats, however, are masters at masking pain. Instead of limping, they adapt by avoiding movements that hurt. Signs of arthritis include:
- Struggling to jump onto furniture or counters.
- Choosing lower resting spots.
- Litter box accidents because climbing in is painful.
- Less grooming, especially in hard-to-reach areas.
- More irritability when handled.
Research shows that up to 90% of cats over 12 years have arthritis on radiographs ("X-rays"). Yet only a fraction of cats are diagnosed, because the signs are subtle.6 Surprisingly, cats with arthritis often become more vocal, especially at night, and sometimes even more affectionate. They may cling to you for reassurance or cry out when pain flares suddenly.
Thirst and Restlessness Could Be Signs of Chronic Kidney Disease (CKD)
CKD is one of the most recognized conditions in older cats. It develops slowly, often going unnoticed until the kidneys are significantly impaired. Cats with this disorder often:
- Drink more water than usual.
- Urinate larger amounts in or, at times, outside the litter box.
- Weight loss despite a decent appetite but decrease in appetite can also be a symptom.
- Restlessness, pacing, or crying at night.
One study revealed that increased thirst and urination often show up months before diagnosis. Owners also reported increased vocalization — sometimes daytime "talking," but especially loud nighttime cries.7 These behaviors may seem like quirks, but they are actually red flags for kidney stress or high blood pressure, a dangerous complication of CKD.
Hyperthyroidism — A Body in Overdrive
Hyperthyroidism is another common senior cat illness, typically diagnosed at 12 to 13 years of age on average. An overactive thyroid gland pumps too many hormones into the bloodstream, speeding up metabolism.8 A cat with this condition may exhibit certain behaviors, such as:
- A ravenous appetite with steady weight loss.
- Restlessness, pacing, or inability to settle.
- Excessive vocalization, especially at night.
- Irritability or even aggression.
- A "wired" energy that feels unnatural.
In fact, nighttime vocalization was one of the strongest behavioral signs in hyperthyroid cats. While the hyper energy may make a cat appear lively, untreated hyperthyroidism damages the heart, kidneys, and other organs and, as with CKD, can also result in hypertension.
Cognitive Dysfunction Syndrome — When the Mind Changes
CDS, often called feline dementia, may be the most overlooked illness in older cats. Studies show that about 28% of cats aged 11 to 14 and half of cats over 15 show signs of CDS, but only a tiny fraction are diagnosed.9,10 The signs are remembered with the acronym VISHDAAL:11
- Vocalization — Loud or aimless crying.
- Interaction changes — Clinginess or withdrawal.
- Sleep-wake cycle disruptions — Being up at night, sleeping all day.
- House-soiling — Forgetting litter habits.
- Disorientation — Getting lost in familiar spaces.
- Activity changes — Pacing, wandering.
- Anxiety — Appearing unsettled or restless.
- Learning and memory problems — Forgetting routines.
In one survey, only 12% of owners mentioned dementia symptoms unprompted, but 75% recognized them when asked. That gap shows how often feline dementia is dismissed as "just old age."12
The Challenge of Overlapping Signs
One of the hardest parts about senior cat care is that many diseases share similar symptoms. For example:
- Kidney disease and hyperthyroidism both cause weight loss.
- Arthritis and dementia can both lead to litter box accidents.
- Dementia and kidney disease can both trigger nighttime crying.
This overlap is why veterinary checkups — complete with blood work, urinalysis, and sometimes imaging — are essential. Without testing, it is nearly impossible to know which disease is behind the behavior.
Helping Your Senior Cat at Home
Caring for an older cat does not always mean drastic changes. Small adjustments can make a world of difference.
- Comfort for achy joints — For cats with sore joints, ramps or small pet stairs make it easier to reach favorite spots without painful jumps. Switching to a low-sided litter box helps them step in and out comfortably, and a soft, warm bed in a quiet corner gives them a safe place to rest.
- Hydration support — Hydration becomes more important with age, especially for cats prone to kidney trouble. Keeping several water bowls around the house makes drinking more convenient, and many cats drink more from fountains because they enjoy running water.
Adding water to canned or fresh food is another easy way to increase fluid intake. The recommendation now is that senior cats should "drink" their meals like soup, and dry food is not recommended at all. If your cat is particular about food texture, or is a "dry food junkie," talk to your veterinarian about ways to increase the water content of the food slowly and safely for your pet.13
Studies have shown that for cats on kibble, adding canned food in does not significantly improve hydration, but moving the cats to a fully wet food diet (even if extra water is not added) dramatically improves hydration. - Cognitive support — When cats show signs of confusion or anxiety, consistency helps. Sticking to a regular routine for meals and play can ease stress, while leaving a light on at night prevents disorientation. Puzzle toys or gentle play keep the mind active, and pheromone diffusers can create a calming atmosphere.
- General wellness — Senior cats benefit from veterinary visits at least twice a year. At home, keeping track of changes in appetite, water intake, litter box habits, or behavior in a simple diary provides valuable information to share with your veterinarian and ensures problems are caught early.
Living with a Senior Cat — The Emotional Side
Caring for an aging cat can feel bittersweet. On one hand, these are often the most affectionate years, when your cat spends long stretches curled by your side. On the other, it can be difficult to watch them lose abilities or develop new struggles.
But remember — many of these changes are manageable. Your cat may not be the energetic kitten they once were, but your bond is stronger than ever. To your cat, you are comfort, safety, and love. And that matters more than anything.
Sources and References
- 1,5,6,7,8,9,12 Pets 2025, 2(2), 21
- 2,3,4,10,11 Journal of Veterinary Behavior, May 2023, Volume 63, Pages 16-21
- 13 Cabi Digital Library, August 3, 2021
