Nested PCR on nasal swab samples from foals with respiratory symptoms. Nested PCR amplification products from two equines (E1 and E2) showing respiratory symptoms were analysed by gel electrophoresis. DNA was extracted from original nasal swabs; DNA from the suspension was used as template in the first round. Genomic DNA from EHV-2 strain LK was used as a PCR positive control (PCR+) and H20 as negative control (PCR -). DNA marker φX-174 Hae and λ-RF/Hind III is seen in lane M.