When I was a kid, my family got a kitten and a puppy at the same time. There were no other domestic animals around, so the two had only each other for socializa

When I was a kid, my family got a kitten and a puppy at the same time. There were no other domestic animals around, so the two had only each other for socialization. The dog apparently observed how much attention the cat got when it purred, so it developed a habit of making a strange guttural noise when it was petted. We figured it was trying to purr.