Letter Re: De-Worming Livestock, Post-TEOTWAWKI

Mr. Rawles,
I have just finished reading your book How to Survive the End of the World as We Know It and found it very helpful and enlightening. There is one thing I was wondering and can’t seem to find an answer anywhere.
Owning horses in an extended grid-down situation presents the question of worming. After most worming meds has been used or expired how would you treat your horse for worms? I’ve read about using different herbs but wonder about their safety and dosages.
Thank you, – Michael N. in Arizona

JWR Replies: As with most medications for humans, the expiration dates marked on veterinary medications are very conservative. Stock up when you find de-worming paste on sale. Perhaps a reader could chime in with some herbal or 19th Century do-it-yourself alternatives.