How to recognise early kidney disease in older cats

Kidney disease is common in ageing cats, yet its first signs can be so gradual that they are mistaken for normal ageing. A cat may continue to eat, sleep and use the litter tray while its kidneys slowly lose the ability to concentrate urine and remove waste from the bloodstream.

Early veterinary attention can help identify chronic kidney disease before a cat becomes seriously unwell. Regular examinations, blood pressure checks, blood tests and urinalysis are especially valuable for senior cats, including those that appear comfortable at home.

Watch for changes in thirst and urination

One of the earliest clues is a larger volume of urine. You may notice heavier litter, more frequent tray visits or urine outside the tray. A cat that previously drank very little may begin visiting its water bowl repeatedly, seeking taps or licking condensation from sinks and showers.

These changes happen because damaged kidneys struggle to conserve water. Increased thirst and urination can also occur with diabetes, hyperthyroidism, urinary tract problems and some medications, so they should not be used to diagnose kidney disease on their own.

In Australia’s warmer regions, such as Brisbane or Perth, cats may naturally drink more during hot weather. The important detail is a persistent change from your cat’s usual pattern, particularly when increased drinking continues through cooler days.

Notice weight loss and appetite changes

Slow weight loss is another early warning sign. The change may be difficult to see under a thick coat, but you may notice a looser collar, a more prominent spine or hips, or less muscle along the back legs. Weighing an older cat every few weeks can reveal a trend that casual observation misses.

Some cats remain hungry but lose condition, while others become fussy or leave food behind. Nausea caused by waste products in the bloodstream may lead to lip-smacking, drooling, repeated swallowing or occasional vomiting. Bad breath with a chemical or ammonia-like smell can occur in advanced cases and requires prompt veterinary assessment.

Australian owners often rotate between supermarket food, premium diets and prescription products depending on availability and price. Sudden food changes can affect appetite, so record what your cat eats and report the pattern rather than assuming it is simply becoming fussy.

Look at behaviour, coat and hydration

A cat with developing renal problems may become quieter, sleep more or stop jumping onto favourite furniture. Reduced grooming can leave the coat greasy, dry or matted. Some cats withdraw, while others become unusually needy. These subtle behavioural changes may reflect nausea, dehydration, weakness or high blood pressure.

At home, gently observe the gums and overall condition without forcing the mouth open. Sticky gums, sunken eyes, weakness or skin that appears slow to settle can indicate dehydration, although home checks are imperfect. Never delay care if your cat is repeatedly vomiting, cannot keep water down, collapses or stops urinating.

Outdoor cats in Sydney, Melbourne and other Australian cities may drink from pools, puddles or neighbours’ bowls, making their water intake hard to track. Providing several clean bowls indoors, away from food and litter, makes changes easier to notice and encourages hydration.

Arrange screening before illness is obvious

A veterinary examination can detect problems that are invisible at home. Blood testing may include creatinine, urea and SDMA, while urine testing assesses concentration, protein loss, blood, infection and other abnormalities. A blood pressure reading is important because hypertension can damage the eyes, brain, heart and kidneys.

Your veterinarian may recommend imaging, such as an ultrasound, if stones, obstruction, structural abnormalities or another condition is suspected. Kidney disease is staged using the overall clinical picture rather than one isolated result, and results can be affected by dehydration, muscle loss or recent illness.

For senior cats, routine screening is often more useful than waiting for severe symptoms. A baseline result gives the veterinarian something to compare at future visits and may identify a gradual decline while your cat still has a good appetite and normal daily habits.

Make home observations part of care

Keep a simple record of drinking, urination, appetite, vomiting, weight and energy. Measuring water in a bowl can provide useful information, and clumping litter makes changes in urine volume easier to spot. If several cats share a tray, add another tray temporarily or separate them for short periods so individual habits are clearer.

Wet food can increase water intake, and some cats respond well to a water fountain or multiple bowls. Any dietary transition should be gradual. If renal disease is diagnosed, a veterinary renal diet may help manage phosphorus and protein levels, but acceptance matters; a cat that refuses food needs prompt advice rather than prolonged fasting.

Australian pet owners should also avoid giving human painkillers or unapproved supplements. Medicines such as ibuprofen and paracetamol can be dangerous or fatal to cats. Veterinary medicines are regulated in Australia, and prescription treatment should come from a veterinarian who has properly assessed the animal.

Support kidney health with a tailored plan

Management depends on the cat’s stage, blood pressure, urine findings, hydration and other conditions. Treatment may include a renal diet, anti-nausea medicine, phosphate binders, blood pressure medication, potassium support or fluids. Some cats benefit from carefully taught fluid administration at home, while others need clinic-based treatment.

A calm home visit can be particularly helpful for cats that become distressed during car travel. Mobile Veterinary Service provides in-home wellness and preventive care for pets around Greater St. Louis, and owners can review its service area when considering a house-call appointment. Home examinations may also make it easier for the veterinarian to understand litter placement, feeding routines and hydration access.

Kidney disease cannot usually be reversed, but early management can protect remaining function and preserve comfort. Follow-up testing helps adjust treatment as the condition changes. Appetite, hydration, mobility and enjoyment of familiar routines are all important measures of quality of life.

If your older cat is drinking more, producing larger amounts of urine, losing weight or behaving differently, book a veterinary assessment rather than waiting for the signs to become severe. Bring a medication list, food details and notes about litter-tray habits so the veterinarian can build a clearer picture from the first visit.