[Yorky]

I bagged some of this recently from a heap that was being removed so was able to get the old well-rotted manure. Afterwards it struck me that the wood shavings it contains may contain chemicals but then again so would chicken manure pellets.

Does anyone know about chemicals in wood shavings used for animal bedding?

[Liparis]

As far as I know they aren't medicated. Check with a supplier they should be able to tell you if they are or not. I've never seen anything printed on the bales I've bought, which I think would be a legal requirement. Small packages of sawdust/shavings sold for guineapigs etc in pet shops are possibly medicated.
Bill.