Not necessarily. Things like age, time spent in the fandom and views of unrelated topics are more accurate givaways to their opinions. You'll find that a lot of them don't even like the fandom.
I don't know what traits they're showing that make them look like a furry, but if, for example, they like to draw anthropomorphic characters or one in partilucar, I'd ask if they're into things with such types of characters or what they like to do with their own.