Updated EVA Guidelines now available on AAEP website

The AAEP has updated its Equine Viral Arteritis (EVA) Guidelines to amend the treatment protocols for this infrequently diagnosed but important systemic disease that continues to impact trade by restricting the export of carrier stallions and virus infective germ plasm.

EVA is a contagious viral disease of equids in which widespread vasculitis may result in non-immune individuals, leading to fever, peripheral edema, pneumonia and abortion. Infection can vary from inapparent to fulminant clinical disease in young foals. Mortality is rare in otherwise healthy adult horses.

No specific antiviral treatment for EVA is currently available. Practitioners should observe the following treatment recommendations:

• Supportive therapies are indicated in moderate to severe cases of the disease, and specifically important in clinically affected stallions.

• Elimination of a carrier state is problematic. Because the virus is shed in semen, castration is the only reliable method for elimination of the career state.

• Non-surgical strategies such as the use of GnRH antagonist or anti-GnRH vaccines, may facilitate clearance in some stallions, but these methods are not fully validated and may have deleterious effects on libido and sperm production.

“Capable of being transmitted by respiratory and venereal routes, equine arteritis virus has the potential to cause extensive outbreaks of abortion, deaths in young foals, and the carrier state in stallions,” said guidelines reviewer Dr. Peter Timoney, professor emeritus at the University of Kentucky’s Maxwell H. Gluck Equine Research Center. “A safe and effective vaccine is available for immunizing stallions and non-pregnant mares.”

View the updated EVA Guidelines or save them to your tablet or mobile device at https://aaep.org/resource/equine-viral-arteritis/.