But the search was called off after heavy rains made the search too difficult.
The horses were found roaming in the area of NW 97th Avenue and 154th Street in Hialeah. Six of them were rounded up on Friday and another five were herded up on Saturday.
One of the horses found Friday was a pregnant pony with a broken leg.
The organization said they've been unable to find the horses' owners, and they're rounding them up for fear they might starve to death or possibly die as they get closer to high-traffic roads.
“We believe that there are at least 10 more horses out there that need to come in. The area where they are is accessible only on horseback. We are making plans to do just that to save these horses from starvation and to prevent them from reaching public roads," said SFSPCA president Jeanette Jordan in a statement. "Clearly the horses are becoming more desperate for food and we must help them."
All the horses are being brought to the SPCA's rescue ranch, joining another 40 or so rescued horses already there. The non-profit said it can't care for all of them without the public's help. They're asking for donations or people to adopt the horses.
For more info go to www.helpthehorses.org.