Oral vesicular lesions in horses without evidence of vesicular stomatitis virus infection.

Objective—To report clinical and serologic findings in horses with oral vesicular lesions that were consistent with vesicular stomatitis (VS) but apparently were not associated with VS virus (VSV) infection. Design—Serial case study. Animals—8 horses. Procedure—Horses were quarantined after appearance of oral lesions typical of VS. Severity of clinical signs was scored every 2 to 5 days for 3 months. Serum samples were tested for antibodies by use of competitive ELISA (cELISA), capture ELISA for IgM, serum neutralization, and complement fixation (CF). Virus isolation was attempted from swab specimens of active lesions. Results—2 horses with oral vesicular lesions on day 1 had antibodies (cELISA and CF) against VSV; however, results of CF were negative by day 19. Five of the 6 remaining horses were seronegative but developed oral lesions by day 23. Virus isolation was unsuccessful for all horses. Conclusion and Clinical Relevance—Horses were quarantined for 75 days in compliance with state and federal regu...