Equine viral Arteritis: current status in Argentina

VISSANI ALDANA; IGLESIAS MARCELA; ECHEVERRIA MARIA; TORDOYA S; LA TORRE J; METZ GERMAN; BECERRA L; SERENA M; BARRANDEGUY M

Lexington Kentucky, USA

Workshop; Second Internacional Workshop on Equine Viral Arteritis; 2008

University of Kentucky

Equine viral arteritis (EVA) is considered a notifiable disease by OIE. In Argentina the virus neutralization test (VNT) is the official test used as part of an EVA surveillance program (all registered stallions of all breeds must be EVA-tested once a year-Resolution N° 434/01), as a requirement for horses to enter the country and also for the export of Argentinean horses (depending on the import requirements of the destination country). In addition, virus isolation/test mating must be carried out on all vaccinated seropositive stallions and imported semen before use. Stallions testing positive by VNT without an official certificate of EVA vaccination must be withdrawn from commercial breeding. This presentation summarizes the findings of the stallions' surveillance program, obtained from the three officially approved laboratories that carry out the EVA test, over the last three years. We also present the results obtained from all horses EVA-tested at the INTA laboratory during 2007. The following number of stallions were tested: 1208 in 2005, 1362 in 2006 and 1283 in 2007. No EVA-seropositive stallions were found among local breeding stallions. However, 7, 2 and 10 thoroughbred stallion, all of which had been imported several years before and had been EVA-vaccinated in the country of origin (The United States and France), were found EVA-seropositive in 2005, 2006 and 2007 respectively. We tested 4133 horses (either import/export animals) at the INTA laboratory during 2007, 49 of which were found positive. These included 25 thoroughbred shuttle stallions that had entered the country for the breeding season, 1 Arabian stallion acquired in Europe for breeding, 7 jumping mares imported from Europe, and 16 locally bred jumping horses belonging to breeding farms which had experienced equine arteritis virus infection. Even though there is still a small number of EVA-seropositive horses among native Argentinean horses, all of them are on jumping horse breeding farms where active infection was confirmed (by serology and virus isolation) and controlled several years ago. From these data, it is possible to conclude that the EVA situation on Argentinean breeding farms, equine sport clubs, stables and hippodromes is not a cause of current concern. These results also reinforce the need to continue with the control of EVA in all horses and semen entering the country as well as with the national surveillance program in order to maintain the current EVA "free status" in Argentina