Rebrascora, you live in a cooler climate. Your soil will be cooler as well, which is not very conducive for worms. It's the same for northern parts of the U.S.
The fact remains that soil is contaminated with eggs and will be picked up by other birds.
Only continued treatment over a period of...
You saw a large roundworm. Worms dont leave their host. The only reason you saw it in feces was that it was dead or dying and was excreted. The other reason is that there wasnt anymore room in the digestive tract for it and it was excreted.
One female roundworm lays hundreds of eggs per day onto...