Short answer: cats have a body structure that makes them prone to fatty liver (hepatic lipidosis) even after a relatively short fast, so if your cat refuses food for more than a day, it's important to get veterinary care quickly rather than waiting for things to improve on their own.
Why are cats at risk from even a short fast?
Cats are less efficient than other animals at converting body fat into energy, so even just a few days without eating can lead to excessive fat buildup in the liver, causing fatty liver.
What are the 2 risks that fatty liver creates?
① Liver function itself declines, which can lead to whole-body symptoms like jaundice and vomiting ② Once it progresses, recovery takes a long time and treatment becomes difficult, which can worsen the overall outlook. These are the two main risks of fatty liver.
Which cats are especially at risk?
Overweight cats that suddenly stop eating are known to be at particularly high risk for fatty liver, so loss of appetite in an overweight cat calls for faster action.
How long should I wait once loss of appetite starts?
Not eating anything for more than 24 hours is a safe cutoff for getting veterinary care without delay. If your cat's condition is already compromised by another illness, you should seek care even sooner.
Is there anything I can try at home first?
Warming up highly palatable wet food slightly to intensify the smell can help encourage eating, but if there's no response even to this, don't delay — head to the vet.
