Disease Watch: Equine Piroplasmosis Case in Missouri

by Fran Jurga | 13 June 2009 | The Jurga Report
According to the Animal and Plant Health Inspection Service of United States Department of Agriculture, a horse in Jackson County, Missouri has tested posted for equine piroplasmosis, a tick-borne disease. The affected horse is a seven-year-old Quarter horse gelding purchased six months ago and has been housed on the owner's premises since then. In addition to the affected horse, there are 63 other animals on the property including horses, ponies and mules. A quarantine is in effect.

On June 2, the affected index horse was presented to a veterinary medical hospital in Kansas for acute illness consistent with infection of a blood-borne pathogen. The horse was placed under quarantine and isolation. The following day, laboratory samples were submitted to the National Veterinary Services Laboratory (NVSL).

On June 6, the Missouri Department of Agriculture issued a written quarantine of the affected premises. A subsequent inspection of the animals and the premises revealed no ticks.

When the tests came back on the horse revealing a positive result for equine piroplasmosis (Theileria equi), plans were made to test additional horses on the premises.

Click here for a USDA document with more information about equine piraplasmosis. You might also like to read about the cases in Florida last year; check the August and September 2008 archives of The Jurga Report by scrolling through the list of archives in the right-hand column of the blog.

Great News for 2010 World Equestrian Games: Piraplasmosis Will Not Prevent Horses or Nations from Competing

Note: This press release arrived today and is a great advancement for a true "world" World Equestrian Games (WEG) in 2010 at the Kentucky Horse Park. For many years, horses from countries where piraplasmosis is a problem have been prevented from entering the USA. This restriction has caused disappointment for many countries in the past. Today's announcement is great news!

I am posting the entire press release from the USA WEG offices so blog readers can learn more about the new procedure and also more about this international disease control issue. Here's the official news:

After years of research and planning, a much awaited plan that allows piroplasmosis positive horses to compete in the Alltech 2010 World Equestrian Games (WEG) was announced at November’s FEI General Assembly, by the World Games 2010 Foundation in coordination with the Kentucky Department of Agriculture (KDA) and the USDA’s Animal and Plant Health Inspection Service (APHIS). The Games will be held in Lexington, Kentucky at the Kentucky Horse Park September 25 to October 10, 2010.

“Effectively negating the piroplasmosis risk for both competition horses and the domestic horse population is a primary focus for our team, as part of our overall importation and quarantine plan,” said Dr. Kent Allen DVM, 2010 Games Veterinary Services Coordinator. “We want all horses to enter a healthy environment, and to leave the Games from a healthy environment.”

Piroplasmosis is an equine blood-borne disease, causing sickness in horses that have not been exposed to the disease before. In areas of the world where the disease is more common, it can be transmitted by carrier horses that have encountered the disease previously and carry both the organism and antibodies in their blood.

The piroplasmosis organism requires specific tick species to complete its life cycle. For the organism to spread, this species of tick must feed on an infected horse, then drop off and feed on a non-infected horse. The protective control plan consists of multiple factors designed to reduce the prevalence and introduction of ticks to the environment in and around the Kentucky Horse Park.

Over the past several years, the USDA, KDA, and APHIS have conducted extensive studies and testing to better understand the area’s tick population. The studies identified that the tick population drops significantly during the fall season when the Games will be held.

“The health and well-being of the horse is at the core of everything we must do in preparation for these Games,” said World Games Foundation Chairman John Long. “We are fortunate to have a team of state and federal agencies working with veterinary officials and experts to ensure that all horses enter and leave the country in the best environmental circumstances.”

Multiple tick mitigation practices and policy will be implemented to further reduce risk. These practices include natural tick barriers, establishing designated grazing areas treated with tick retardant agents, and separate stabling and frequent inspection of horses upon reentry into the stables.

Horses will be treated with an equine de-wormer that effectively kills attached ticks prior to entry. In addition, piroplasmosis-positive horses will be shipped directly from their federally-mandated quarantine center to special stables within the Kentucky Horse Park, and will also be required to leave the country directly from these stables.

“The Kentucky Department of Agriculture is confident that these procedures will protect all horses at the 2010 Games,” said Agriculture Commissioner Richie Farmer. “We are supportive of the Foundation’s efforts to ensure the health and safety of both competition horses and the domestic horse population.”

These protective strategies will allow the entire park to be utilized by all competition horses during the 2010 Games, while providing the needed assurance that the U.S. domestic horse population is not put at risk.