The first incident occurred as the parade was just getting started near Del Obispo Street and Ortega Highway around 11 a.m.
Orange County fire officials say two horses pulling a trailer apparently got spooked and ran through a sign and into the crowd. One of the horses fell on several bystanders.
A 53-year-old double amputee suffered moderated injuries and was transported to a local hospital. Two women suffered minor injuries.
The horse was able to get back up on its feet and continue the parade.
In a similar incident that happened around 12 p.m., a 55-year old woman fell off a small chariot being pulled by a mini horse. The woman was taken to the hospital with a head injury.
In a separate incident prior to the parade, a 57-year-old man died after suffering a heart attack in front of Sarducci's restaurant.