Florida's Agriculture Commissioner Charles Bronson said today that the last premises determined to have had horses infected with the disease had now been released from state quarantine.
The department's animal industry division began to investigate and response to the outbreak on August 13 last year, when an ill horse was admitted to a veterinary hospital was diagnosed with the disease.
Equine Piroplasmosis is a blood-borne parasitic disease of horses and is listed as a foreign animal disease in the United States. The country had been considered free of EP since 1988 until the outbreak in Florida.
"I believe a quick and thorough response to the outbreak by our Division of Animal Industry helped to keep it relatively contained," Bronson said. "I am pleased and relieved that we have been able to eradicate it in a short period of time."
The disease is primarily transmitted to horses by ticks or contaminated needles.
It is not directly contagious from one horse to another but requires direct blood transfer. Acutely affected horses can have depression, fever, anaemia, jaundiced mucous membranes and low blood platelet counts.
EP can also cause horses to have roughened hair coats, constipation, and colic. In its milder form, the disease causes horses to appear weak and show lack of appetite. Some horses become chronic carriers of the disease.
During the disease investigation, 25 premises were quarantined and 201 horses were tested for the disease.
In all, 20 horses on seven premises were determined to have been infected with EP although the majority of the horses did not show any symptoms.
Currently, no horses testing positive for the disease remain in Florida.
Despite extensive tick surveillance, the Division of Animal Industry was not able to locate any ticks that carry the disease and believe it was spread through contaminated needles or blood transfusion.
In order for a quarantine to be lifted from a premises, all horses must test negative, have no exotic ticks found, and no domestic ticks determined to be infected with the EP organism.
Because they can continue to be carriers of EP, horses that test positive for the disease must remain quarantined for life, be euthanatised, be shipped to a research facility in the United States or be shipped to another country.
Now that the last quarantine has been released, Florida and the mainland US are considered free of the disease.