as I say I haven't tried it with pigs , but farmers were doing all sorts of tests with comfrey , all reported in LDH's book , and some were feeding huge amounts of it to pigs daily without any bad side effects. So I can see no reason it will harm any of the pigs, just don't go from pig nuts to all comfrey in a day , that would be pushing things a bit to fast . I know with the calves I was looking after , some were with their mums , some were fed with a bucket, but all were given the wilted or chopped comfrey , and all recovered well. In the main i have found that it has been calves inside that have had scours , same with pigs I have known about , but those outside that I have looked after have never had them . That doesn't mean they never get it !! just the ones I have had anything to do with have been fine if they were outside. With the weather as it is now, in the UK , it should be ok to have them outside . The more fresh air they get the better, they don't need to be in now , unless they are in for other reasons ? They really only need cover from sunshine and heavy rain now. Scours can have different causes I know , but one thing I do know is that warm closed in areas, are more prone to causing and spreading it than fresh air. There are many pig keepers on the forum who have no doubt had pigs with scours , and they will have their own way of dealing with it . No doubt things have improved since I looked after stock , but comfrey does work and is free if you have some growing near you .
Cheers
Russ