Sans sifting through the birthdates of celebrity veggos & vegans (another job for my imaginary astrological intern) – coming up with astrological vegetarian/vegan indicators is guesswork. I’m vegetarian and have been since age five – Anecdotally, I know a lot of Pisceans who are veggo & a strong Neptune (ruler of Pisces, compassion, empathy) can also predispose one. There are Scorps who wear fur and relish red meat a la Anna Wintour and there are Scorps such as Joaquin Phoenix, who are strict vegans & do stunning docos like Earthlings about it.
You could also argue that it is Uranus/Uranian if the choice is less compassionate & more New-Agie logic re resources et al. And indeed, Aquarian veggos also seem to disproportionately high. I’m thinking Neptune in Pisces (2011!) will see a big spike in the veggo ranks…i note that nearly all the females in my teenage son’s set are vegetarian – the Pluto in Scorpio generation girls, not sure where that’s coming from exactly.