Stevens wrote this about a dachshund he found tied to a post when he was young. When nobody claimed the dog, he took it home and grew attached to it. According to the United States Humane Society, four million cats and dogs per year are put down because they cannot find a home. They recommend spaying and neutering to help control the breeding of more unwanted pets. Among many celebrities who help get the message of humanity to animals out, long-running TV game show host Bob Barker made a pitch for this message at the end of most episodes of the Price is Right.
This was Stevens' first single. It became a hit on pirate radio stations in England, helping launch his career.
Producer Mike Hurst, who was a former member of the Folk-Pop group The Springfields, heard Stevens play this and had him record it. Stevens got a record deal with Dream (an imprint of Decca designed as a showcase for British talent) and within 3 months this became a UK hit.
The B-side to this song, "Portobello Road," is an actual street in west London, England, famous for it's open-air flea-market. It was also commemorated in the little-known 1971 Disney film Bedknobs and Broomsticks.
In 1976, Stevens converted to Islam. This happened after a near-death experience off the coast of Malibu, California, during which time he believes that he was spared to do God's work. After converting to Islam, he changed his name to Yusuf Islam. He continues to answer to the title to this day, having started releasing Islamic gospel music in the 1990s.
The name change has a link to this song, because Stevens revealed that the tune was inspired by "The Plum Blossom" by jazz musician Yusef Lateef.
We'd just like to point out the irony of a singer named Cat Stevens making this song.