Experimental Seneca Valley Virus Infection in Market-Weight Gilts

Seneca Valley virus (SVV) is a picornavirus that causes vesicular disease in swine. Since it is clinically indistinguishable from vesicular disease caused by food-and-mouth disease virus (FMDV), investigations must be performed to rule out this high consequence pathogen. A large portion of these investigations have involved market-weight swine at slaughter plants. The objective of this study was to describe acute infection dynamics of market-weight gilts (8 months of age) experimentally infected with SVV. At 0 days post inoculation (dpi) all gilts (n = 15) were given an intranasal SVV inoculation. Vesicular lesions on the coronary band were first observed on one or more feet by 2 dpi in 4 of the 15 gilts and in all by 5 dpi. Vesicles on the snout were observed in 6 of the 15 gilts beginning at 4 dpi. All gilts became viremic post challenge for about 7 days and developed anti-SVV neutralizing antibodies by 7 dpi. Most vesicular lesions were resolved by 14 dpi. Understanding the pathogenesis of SVV is critical in order to inform decisions that veterinarians and producers must make at the farm level to control this disease.