Rat Lungworm

[Midnight Rambler]

Snail and slug baits containing iron phosphate are safe to use around pets and other animals. I've had good success in controlling slugs with them for a pretty long time after a single treatment; the pellets do turn to mush in the rain though, so it's best to do it at a time when it's humid and damp (so the slugs are active) but not raining for a few days.

The infectious worms are actually relatively large, about 500 microns long by 25 microns wide. So any sediment filter tighter than 25 should keep out the worms if you're drinking catchment water; typically they're 5 or 10 microns. Of course, you shouldn't be drinking it with only that level of filtration anyway, because all kind of bacteria (including leptospirosis) will still be getting through.

EDIT - apparently a study has been done finding that they do get through a 20 micron filter, which is the minimum recommended. Still, the general point still stands, since most people should be using a 10 micron filter at least if there's no disinfection system, or else a 20+5 with a disinfection system (it's not clear if UV kills the worms like it does bacteria).