New research suggests that snails and slugs may transmit P. ramorum spores

Hyder, N.; Coffey, M.D.; and Stanghellini, M.E. 2009. Viability of oomycete propagules following ingestion and excretion by fungus gnats, shore flies, and snails. Plant Disease 93:720-726.

Abstract: Sporangia of Phytophthora capsici and P. nicotianae, as well as hyphal swellings of Pythium splendens, P. sylvaticum, and P. ultimum, were ingested by adult shore flies but none were viable after passing through the digestive tract. Oospores of Pythium aphanidermatum retained their viability following ingestion by adult shore flies. Larval stages of fungus gnats and shore flies ingested sporangia of Phytophthora capsici, P. nicotianae, and P. ramorum, but they were not viable upon excretion. In contrast, hyphal swellings of Pythium
splendens, P. sylvaticum, and P. ultimum, chlamydospores of Phytophthora ramorum, and oospores of Pythium aphanidermatum, retained their viability after passage through the digestive tract of these larvae. Snails were capable of ingesting and excreting viable sporangia and chlamydospores of P. ramorum, which upon excretion infected detached leaves. Although the impact of larvae and snails in the rapid dissemination of pathogen propagules is unknown, this work does highlight the possibility that some often-ignored animal–fungus interactions should be considered in long-range dispersal of pathogen propagules via food webs.