Why the number on the scale misleads
A senior cat can weigh exactly what she weighed last year and be in noticeably worse shape. Ageing cats commonly lose muscle from the hindquarters, thighs and along the spine — the bony, scrawny feeling of an old cat — while keeping, or quietly adding, fat over the ribs and belly. The scale adds those two opposite changes together and reports that nothing happened. Weight still matters, but for an older cat it only makes sense alongside body condition: what your hands find when you feel her ribs, spine, hips and belly tells you which tissue is changing, and that is what should guide feeding.
Learn to score condition with your hands
Once a week, when she is relaxed, run flat palms lightly over her ribcage: you should feel ribs under a thin layer of fat with gentle pressure, not hunt for them and not trip over them. Stroke along her spine and over her hips — the bones there become prominent as muscle fades, even in a cat who looks plump from above. Look at her from the side and from overhead: a healthy senior keeps a slight waist, while a sagging, rounded belly with bony shoulders is the classic picture of fat gain masking muscle loss. Use the same routine, in the same order, each week, and write down what you felt in plain words. Consistency matters more than perfect scoring technique.
Feed for muscle, at steady times
Keeping an older cat stable means feeding to protect muscle, not simply cutting or adding calories. Offer measured meals of a good-quality senior or adult food with plenty of animal protein, served at consistent times so you can see exactly what was eaten — grazing from a topped-up bowl hides both appetite loss and overeating. If she is losing condition, add a small extra meal rather than suddenly enlarging portions, and warm wet food slightly to raise its smell appeal. If she is gaining fat while still losing muscle, do not crash-diet her: overweight senior cats still need protein and gentle portion control, and rapid weight loss is risky for cats. Any clear change in either direction is a conversation to have with your vet, ideally armed with your weekly notes.
Movement that preserves what she has
Muscle that is never used disappears faster. Short, low-impact play — a toy dragged slowly along the floor, a feather to bat from her bed, a few steps of following you to a treat placed a short distance away — asks her hind legs to work without jumping or twisting. Two brief sessions a day suit a senior better than one long workout, and stopping while she is still interested protects stiff joints. Steps or a ramp to a favourite perch keep climbing muscles in gentle use. If she stops joining in, sleeps through sessions she used to enjoy, or struggles to rise after resting, mention it at her next vet check rather than assuming it is simply age.
Track condition and weight as a pair
Keep one running record with two columns: the scale weight when you can get it calmly, and your hands-on condition note for the same day, plus anything about appetite or activity. Patterns over six to eight weeks — spine sharper, weight steady, eating well — are far more useful than any single weigh-in, and they help your vet judge whether muscle loss is ordinary ageing or a sign that something else needs investigating. Share the record at every visit rather than summarising from memory. KinsLe's Pet Passport helps by keeping your senior cat's weight and condition notes together with her records in one portable packet, so that paired history reaches the vet intact.