I've tried several different herbal deworming mixes (made my own from recipes) and never found them terribly effective. Much to my dismay. I was dosing quantities of herbs that were becoming costly and the results were marginal. I stuck with my gross chemical dewormers as needed. But I've since adopted a different mentality of "a healthy, nutrified animal
should be resistant to parasites." I focus on wholesome diets and adequate mineral supplementation and have only had to deworm acute cases.
I use herbs for other applications though! Especially wound care and immune support. Whatever I would use on myself, I use on the critters. Hasn't failed me yet.
I have one animal herbal book; The Complete Herbal Handbook for Farm and Stable, by Juliette
de Baïracli Levy. It's got some good pointers in it, though I find it lacking for many of my needs. I don't have horses or sheep, and that's a big focus in her book. She also doesn't talk much about common wound care and how to actually doctor an animal properly. Some folks think her herb recommendations are controversial. But you're going to find that anywhere you look in the herbal healing arts. There's abundant misinformation out there and lots of conflicting opinions on the matter. I like herbal sources that talk in depth about chemical composition of herbs and explain the physiological interactions with the body.
I have another good book that focuses on conventional care, called "Where there is no animal doctor" by Maureen Birmingham and Peter Quesenberry. It's all about addressing common issues and obstacles in animal husbandry. From castration to birthing to broken bones and severe wounds, diseases and viruses... Some of the best info I've taken from it is pointers on how to restrain and handle animals effectively and safely while doctoring them. Especially the pointer on how to move pigs; put a
bucket over their head and tug their tail to back them up to where you want them. We've had to use it and it usually works! Anyway, it's got some practical insight and information, though it focuses on modern
medicinal remedies.