The Cow Parade stampeded into San Antonio in November 2003. We downloaded the city listing, and visited every cow we could find. I've seen plenty of cows in Texas, but these were definitely the ones worth going out and looking for. :-)
Last year, I bought the San Antonio Cow Parade commemorative book on Amazon. I believe there's one available for every city that's hosted the cows.
It would be great to see a horse parade, at some point! :-)