Use of a molecular approach for the definitive diagnosis of proliferative larval mesocestoidiasis in a cat

► Cestode larvae were detected in the thoracic cavity of a cat. ► These structures could not be identified using classical diagnostic methods. ► Larvae were identified as Mesocestoides sp. using molecular-phylogenetic approach. ► Molecular-phylogenetic analyses can be utilised to diagnose animal cestodiases.