Why age compounds the risk
Your senior cat's organs don't process toxins as efficiently as they once did. Even a single lick of isopropyl alcohol hits harder when liver and kidney function may already be slightly diminished. What a young cat might shrug off could overwhelm an older system.
Watch closely for subtle changes—a slight head tilt, hesitation before jumping down from furniture, or less interest in her surroundings. Seniors often show neurological signs before gastrointestinal ones with alcohol exposure.
The acetone factor
Isopropyl alcohol breaks down into acetone in the body—the same chemical in nail polish remover. This secondary toxin is particularly hard on older cats. It disrupts their acid-base balance, which can already be precarious in aging animals.
You won't see the acetone forming, but you might notice its effects: rapid breathing, confusion, or an unusual odor to her breath. These typically appear within two hours if they're going to occur.
Why 'just once' isn't reassuring
A single lick seems insignificant until you consider feline grooming mechanics. Their barbed tongues are designed to pull substances off surfaces efficiently. That one swipe likely transferred more alcohol than you'd expect—possibly the entire amount that was on that spot of the wipe.
At 3 kg, there's no margin for error. The toxic dose for cats is much lower than for dogs, and seniors often react at even lower thresholds. Don't dismiss this because it was brief contact.
Monitoring the subtle signs
With an older cat, you're looking for slight deviations from her normal behavior. Maybe she doesn't greet you as usual, or her purr seems weaker. These soft signs matter more than dramatic collapse when dealing with small alcohol exposures in seniors.
Keep her warm and quiet, and prevent access to high places where she might fall if she becomes unsteady. Even mild intoxication can lead to injury in an older cat who misjudges a jump.
The step-by-step response, from the first minute to the vet visit, is in our Isopropyl Alcohol Poisoning: Emergency Guide emergency guide.