- "I've just came across a big old tomcat or janecat can't tell the difference. How do I tell what sex the cat is before his vet visit on Thursday so I don't look like a complete ding-dong? Thanks."
Of course, it's a somewhat different case when trying to "sex" a kitten. (That's what it's called; I didn't make it up.) Here's How to Tell the Sex of a Kitten.