Vegans generally still believe in self defense, which applies to parasites. You're not morally obligated to degrade your health for another animal, you're just not supposed to kill for frivolous reasons like personal taste preferences, because that's no different than killing for sport.
Vegans avoid killing animals where it is possible and practical. They do not relocate every invertebrate in the soil when they need to build a new house. they certainly still apply different moral weights to different animals.
this ignores veganism as a concept, pretty much. most vegans don't support killing insects
what about mosquitoes or tapeworms
Vegans generally still believe in self defense, which applies to parasites. You're not morally obligated to degrade your health for another animal, you're just not supposed to kill for frivolous reasons like personal taste preferences, because that's no different than killing for sport.
Vegans avoid killing animals where it is possible and practical. They do not relocate every invertebrate in the soil when they need to build a new house. they certainly still apply different moral weights to different animals.