Do you have an older cat that has been inside over winter?
Do you think your cat has good mobility? Are they still able to jump on the sofa with ease?
Have you noticed new cats in your garden?
Our older cats may get bullied as they cannot defend their territories as they get older.
Older cats may not want to go outside to toilet if they feel vulnerable.
Older cats may not toilet as frequently if it is uncomfortable for them to go outside or use a litter tray.
You may need to use a shallow sided tray and soft litter that is nicer for the cat to use.
The use of Pheromone therapy may be useful