The prominade or parade of beasts, at the Blessing of the Animals on Olvera Street at El Pueblo de Los Angeles, has become an excuse to dress up one's pets for a thrilling day of joy, and a priest's sprinkling of holy water on everyone's pets.
The topmost chihuahuas in costumes were photographed by Will Campbell in 2007. Middle and bottom photos from 2007 are by Richard Velasco who lives in Los Angeles.
Though most Blessing of the Animals events throughout the Americas occur in October for the Feast of St. Francis, where Los Angeles is concerned, St Francis is not the inspiration for the fiesta. This has officially been done annually in the spring since 1930, but really much longer since the pre-Anglicized version dates to 1781 in Spanish California.
It still takes place in April (rather than in October as for St. Francis) to take advantage of good spring weather, though originally it was in January for the Feast of San Antonio de Abad. It wasn't until the 13th Century that the Blessing of the Animals became associated with St. Francis, though the blessings themselves date to the 4th Century, and was for a few centuries associated chiefly with the Feast of Saint Anthony of the Desert.
There are other inspirations apart from St. Anthony. In Oaxaca, Mexico, the Blessing of the Animals is associated with the Feast of St. Ramon Nonato, 13th Century Catalonian saint. And when conducted in synogogues, often on the Shabbat of Parashat No'ach (September/October), the rituals, prayers, songs and blessings get their impetus from God having saved the animals during the Flood, and due to God's covenent "with the animals of the field, the birds of the air, and the creeping things of the ground" [Hosea 2:20].