An Ohio horse farm is under a state imposed quarantine after two horses became infected with the equine herpes virus (EHV-1). One has been euthanized.
A Quarter Horse at a Muskingum County farm initially stopped eating, had a fever, and then developed pelvic limb paralysis. Tests confirmed the 15-year-old barrel racer was infected with EHV-1. After being referred to Ohio State University’s Galbreath Equine Center, where the gelding was kept in isolation, the horse went down. The gelding was euthanized on March 21st.
A second barrel racer, from the same farm, started running a fever and exhibited bilateral rear leg ataxia (lack of coordination) on March 20th. The equine was transported to OSU and admitted to an isolation stall. Blood and swab samples were positive for EHV-1. The horse is currently responding to treatment and improving, according to department officials.
Both barrel racers participated in a competition in Springfield, Ohio on March 6th through 7th. A third horse from the farm also participated. It has shown a slightly elevated temperature to date, according to the state.
The farm is under a 30-day quarantine. No horses are allowed to enter or leave the farm and biosecurity measures are in place to prevent the spread of the disease. All remaining horses are being monitored. No horses have left the facility, other than for the barrel competition, in the past 30 days. To date, none of the other animals have shown signs of illness, other than the slightly elevated temperature in the third animal that attended the barrel racing competition.
The EHV-1 virus spreads quickly from horse to horse, has a high morbidity rate, and can cause a wide range of symptoms, from a complete lack of clinical signs to respiratory problems. The neurologic form of EHV-1 can cause an acute paralytic syndrome, which has a high mortality rate.
The incubation period of EHV-1 is typically 2 to 10 days. The virus spreads readily through direct contact with infected materials. While highly infectious, the virus does not persist in the environment.
A barrel racing horse in Michigan was also confirmed with EHV-1 this month before it was euthanized. There is no known relationship between the Ohio and Michigan cases.