They're young... I think the warts are an adolescence thing? My five yearlings at home have them, and twice I've been to youngstock grazing away and the whole mob is warts and ringworm - maybe from an incoming bull? I don't know.
Not a bad move - you don't know why, you don't know the history, there's always good healthy cattle around.
My cows are all snotty nosed right now too, following rain after drought. 'zackly the same thing happened at the end of the dry last year, left me with four cows with permanent catarrh when the rest had recovered. Looked at vaccinating for IBR but I don't think it was that and the vet said it wasn't that...
I think because they've been hard done, they're skinny, cold in the rain, *Jerseys* - don't seem to see that sort of thing when they're mostly strong and healthy.
Anyway, last time I walked away from a sick calf her owners put her back in with the group they were selling me the following week, for free, all better now they said. So I agreed to take her.
She did well until five months old. Died a month later. Cost me nothing but my labour, milk powder, grain feed, vet, medicines...