Street cats aren't a nuisance for 70-year-old Ali Tural; he cares for them with love, and receives praise and donations. For many in Istanbul, affection for cats symbolizes a deep faith in Islam.

In March, Kitakata became an early adopter of CatsMe!, an AI-driven smartphone application that purports to tell when a cat is feeling pain. That cuts down on the guesswork of when it is necessary ...