Health

Equine Piroplasmosis

A tick-transmitted horse disease has been detected on a South Texas ranch.

From the Texas Animal Health Commission

A tick-borne disease known as equine piroplasmosis has been confirmed on a ranch in South Texas. Additional testing is being conducted to determine the extent of infection. Horses on the ranch are quarantined to their premises, and a thorough disease investigation is under way.

Equine piroplasmosis can affect horses, donkeys, mules or zebras and cause clinical signs common to many diseases, including poor appetite and weight loss. Death can occur. Some infected equines may exhibit few or no signs of disease. Those animals that survive the acute phase of infection may continue to carry the parasite, which has been identified as Theileria equi (formerly known as Babesia equi), for long periods of time.

“Although equine piroplasmosis is not considered to be endemic in the U.S., cases have been detected on occasion,” said Dr. Bob Hillman, Texas’ state veterinarian and head of the Texas Animal Health Commission, the state’s livestock and poultry health regulatory agency. “In June, equine piroplasmosis was detected in Missouri, with a related case found in Kansas. In 2008, the infection was detected in Florida. These cases have been closed.”

Equine piroplasmosis may not be that common anymore, but there are plenty of other health issues facing horses and horse owners. Learn all you can with our Common Horse Health Issue report.

“As many as 15 tick species are capable of carrying and transmitting the blood parasite responsible for causing equine piroplasmosis,” Dr. Hillman explained. “At this time, we do not know which species of tick is responsible for transmitting infection on the South Texas ranch. Additional blood and tick samples are being collected and will be submitted for analysis to the National Veterinary Services Laboratory (NVSL) in Ames, Iowa.”

Dr. Hillman said there is no vaccine for equine piroplasmosis, and treatment generally is not effective against this tick-borne infection. To avoid spread of the disease, it is important to eliminate contact with ticks and to prevent the transfer of blood from one equine to another.

“Equine owners may want to consult with their veterinarians for recommendations on preventing tick infestation,” said Dr. Hillman. “If equine animals exhibit signs of illness, a veterinarian should be contacted, so appropriate samples may be collected for laboratory testing. Currently, we have no indication that this tick transmitted disease has occurred at other sites in Texas, but maintaining vigilance for this blood parasite is necessary in determining the extent of this disease situation.”

Due to the outbreak of equine piroplasmosis in the state of Texas, the Canadian Food Inspection Agency (CFIA) has asked the United States Department of Agriculture (USDA) to suspend the issuance or endorsement of export certificates for horses and other equines originating from the state of Texas. The imposed restrictions on the import of equidae into Canada from Texas are effective immediately.

According to the American Association of Equine Practitioners, the 2008 equine piroplasmosis case in Florida was fatal.

A 7-year old gelding, located in Manatee County, Florida contracted the rare parasitic disease, and blood and tissue testing of the horse confirmed the diagnosis. He was euthanized after a three-week bout with equine piroplasmosis. State officials immediately quarantined the premises where the horse was kept, as well as two adjacent properties containing horses, pending determination of their status.

The disease had been eradicated from Florida in the 1980s, and the tick species believed to transmit the disease in other countries had not been identified in Florida in many years.

Due to the outbreak of equine piroplasmosis in the state of Texas, the Canadian Food Inspection Agency (CFIA) has asked the United States Department of Agriculture (USDA) to suspend the issuance or endorsement of export certificates for horses and other equines originating from the state of Texas. The imposed restrictions on the import of equidae into Canada from Texas are effective immediately. Oklahoma, Kentucky, Montana and Washington also have imposed restrictions.

This disease is not directly contagious from one horse to another but requires direct blood transfer. Human infection with equine piroplasmosis is extremely rare.

Visit the AAEP’s Web site for a fact sheet about equine piroplasmosis.

There are many health issues that can become a problem for your equine friend. Make sure you are up to date on all the information with our Common Horse Health Issues report.