In the Mediterranean Sea, the dolphin morbillivirus caused severe mortality among striped dolphins (Stenella coeruleoalba) during 1990–1992 and 2007, although the latter outbreak appeared to be less intense. In response to these events, this study evaluated whether epizootics led to the stranding of typically offshore individuals that would not have been stranded during non-epizootic periods, and how these episodes affected population abundance and age structure. To address the first objective, morphometric data recorded in necropsy reports of stranded dolphins between 1980 and 2024—compiled by the University of Valencia—were analyzed using principal component analysis. To assess the second objective, temporal patterns of stranding frequency and the relative proportions of age classes were examined. Results indicated that dolphins stranded in 1990 exhibited significantly larger multivariate body sizes compared to other years, except for the 1980–1989 period. Regarding morphometry, the principal component most strongly associated with fin measurements revealed that 1990 differed from all periods except 2007, which, in turn, only differed from the inter-epizootic interval. The number of strandings did not decline following epizootics; rather, it increased and stabilized around 2013. Nonetheless, after 1990, the age structure became dominated by calves and juveniles. These findings suggest that during epizootics, particularly that of 1990, individuals exhibiting oceanic morphometric traits may have been stranded, and selective adult mortality may have altered the population’s age composition. Although striped dolphins displayed a distinct trend in stranding frequency compared to other cetaceans, disentangling the effect of the epizootic from that of the establishment of the stranding network in 1990 remains challenging. Overall, the results highlight the potential population-level consequences of epizootics in long-lived species and emphasize the importance of maintaining effective stranding monitoring networks.