RESUMEN
BACKGROUND: Dictyocaulosis is a parasitic disease caused by pulmonary nematodes from genus Dictyocaulus affecting various ungulate hosts. It can cause verminous bronchopneumonia and for heavily infected individuals, fatal outcomes can occur. CASE PRESENTATION: The study describes the case of a male European bison which died three months after relocation from Slovakia to one of the reintroduction areas in NucÈoara village, FagaraÈ Mountains, Romania. Necropsy revealed the presence of pulmonary nematodes in the respiratory tract. Morphology and molecular diagnosis was performed and Dictyocaulus viviparus was identified. CONCLUSION: Rigorous health monitoring is essential to assure the success of reintroduction programs, understanding and preventing infectious diseases and limiting their impact on population health.