I don't know! But that will not stop me from answering the question. V. inaequalis overwinters as the immature sexual state and spreads in spring as airborne ascospores. Asci need to be able to launch spores into the air, which is easy on the surface of a flat leaf on the ground. Leaves eaten by sheep will have been torn into shreds and compacted, so even if the fruiting bodies succeed in surviving in dung, most of them will be unable to launch ascospores.