For about two decades, only occasional mechanical problems could delay polo player Owen Rinehart’s annual trip to South Florida for the start of the winter season.

This year, however, his plans to log early training time were derailed by an equine virus outbreak that has killed five horses and left others under quarantine in Florida.

“Everyone is very professional in my business and takes everything very seriously and takes very good care of their horses,” Rinehart said. “So everything that they can do to possibly prevent any more spread or outbreak, everyone is doing.”

Ten barns in Florida, including eight in Palm Beach County, remain quarantined and officials have treated 10 horses for the virus, state Agriculture Department spokesman Mark Fagan said . State and federal officials have not barred horse shipments into or out of Florida, but have advised owners that some events and barns have imposed restrictions