Health officials say a yearling filly has died of Eastern equine encephalitis virus near Ocala.
Owner Vivi Serena says the horse started acting oddly in late June and died within two days.
The Ocala Star-Banner reports test results confirmed this week that the filly died of the virus. Serena's veterinarian notified Marion County officials of the results.
Since April 22, the local health department has issued four notices of positive tests for the mosquito-borne illness.
The virus can also affect humans and health officials are warning residents to take precautions to avoid being bitten by mosquitoes. In humans the virus may cause fever, muscle aches, headaches and seizures.