Police are investigating following the discovery of a horse carcass near the corner of Northwest 131st Ave and 182nd Street.
Several blocks away they located a blood-spattered van with what appeared to be horse meat stored in coolers.
The killing is the latest in a string of more than 20 horse deaths which have angered residents of southern Florida.
Police believe the animals have been butchered as part of a lucrative black-market trade in horse meat, which can fetch up to $US20 a pound.
There is demand for the meat among the large Cuban expatriate population in the wider Miami-Dade area.
The remains of the butchered horses were often dumped on the rural roadsides in the county.
Florida Governor Crist signed a bill into law which outlaws the transport, buying, owning and distribution of horse meat for human consumption.
The only exception is if the meat is clearly marked and stamped for that purpose, but there are no slaughterhouses in the US licensed to slaughter horses for human consumption.
The new law becomes effective from July 1. A breach will be a felony offence carrying a one-year prison term and a $US3500 fine.