We do themes, but the themes are short-term. So, the whole herd isn't one theme. Sometimes we have all the kids named in their mom's theme (with their dad's initials in their registered name), and sometimes we do all the kids from a group of kiddings with a theme.
So, Alibi's first kidding resulted in Jail Bird and Felony; Peekboo's 1st and 2nd kidding resulted in Tag You're It, Hopscotch, Solitaire and DOuble Dutch; and Amber's 1st kids were Koelsch, Pilsner and Shandy.
The December 2012 kids were all winter/holiday themed: Fudge, Gingersnap, Spritz, Blitzen, Comet, Holly, Marshow (what my son calls marshmallows), and Smudge (like a smudge from soot/coal, she is a tricolor out of two light gold and white parents, sure surprised us!)
The juniors kidding over the next few weeks will have their kids named in their own themes. So DOuble Dutch's kids will all be single/double/triple type names; Pilsner will have drinking type names; and Jail Bird will have "bird" type names.
Our human kids have a theme too, lol. They are all place names.