What was this view exactly? They would have know their pets and farm animals reproduced sexually. I guess it isn't a leap to think all mammals? So what animals did they think did not?

So, we tend to think that it’s just common sense that most animals reproduce sexually (actually I think most people would assume that _all_ animals do; in fact, as with most things, there are edge cases), but, well, to an extent that’s because we already know that. The historical view was a bit different: https://en.wikipedia.org/wiki/Spontaneous_generation

This isn’t even the only weird idea that people used to have about reproduction; there’s also stuff like https://en.wikipedia.org/wiki/Barnacle_goose_myth

Mice, flies, vermin of various kinds that seemed able to show up anywhere from no obvious parents.