It's August so there are lots of snail stories about again. This week it's about snails being responsible for spreading lungworm to dogs. The article in each newspaper is almost identical so I suppose they must have simply reprinted the press release from Exeter University. It came with beautiful illustrations of sparkling Led lights on snails wandering around in the dark so that was a bonus. It's only the headline that's different depending on the style of newspaper concerned and mostly focused on the idea that snails were spreading lung disease amongst dogs. At least Radio 4 didn't make a crisis out of a simple piece of ecological research that apparently just watched snails moving about.
If you want to understand parasites you need to know the whole life cycle. This parasitic worm affects foxes as well as dogs - though, importantly, it doesn't affect humans. I looked up Angiostrongylus vasorum to try and find out its life cycle. According to Wikipaedia - not always a reliable source for scientific information but this looks like a reasonable article - foxes are thought to be a reservoir for the disease. If you think about it rationally for a moment, snails we know have a homing instinct implying they don't travel far. Foxes on the other hand would range over a much wider area infecting lots of slugs, snails and other internediate hosts. Slugs and snails get infected because the larvae of the worm burrow into the mollusc's foot. Perhaps foxes are more important as an agent that spreads the infection from place to place. But dog hygiene has got to be an important factor too. If you let your dog defaecate all over the place, is it any wonder that molluscs get infected too? (http://en.wikipedia.org/wiki/Angiostrongylus_vasorum) One message that seemed to come from the research is not to leave dog toys out in the garden overnight. But the research is said to have been funded by Bayer Health with the aim of investigating lungworm so I can't help thinking there had to be more to it than just watching snails wandering about.