[Lightning strike on a horse pasture - a diagnostic challenge?!]

During summer, permanent or temporary pasture keeping carries an increased risk of death caused by lightning strikes. Although - due to their body structure and pasture grazing - large animals are particularly susceptible to step voltage effects in consequence to a lightning strike to the ground there are only few published cases in the veterinary literature. Frequently in lightning-related accidents, a current flow through the heart occurs resulting in acute cardiac and circulatory failure. In the vast majority of cases, this is accompanied either by very unspecific lesions or even lacks any morphological alterations. Accordingly, the etiologic diagnosis in the absence of clear, lightning-related damage to the body represents a major diagnostic challenge. The evaluation of meteorological data as well as consideration of the pasture's location and positioning of the body when found may provide further key information in the clarification of fatalities caused by lightning strikes.This case report presents findings in a 7-year-old thoroughbred gelding found dead together with 3 other horses, all lying together in a group on the pasture. Pathological examination revealed a 2-3 mm wide line of singed, curled hair on the right front and hind limbs. Histologically, the pertaining skin areas displayed groups of elongated epithelial cells with herringbone-like elongation of the nuclei within the epidermis and the hair follicles. Coagulations of dermal proteins were present multifocally within the dermis.