From personal experience, anon + immediate family has had much success with ivermectin.
Anon took before conceiving and when pregnant
Anon took while nursing multiple times
Anons < 5, < 3 and 18mos
None of us have grown a tail btw
So true, many farmers I have spoke to that deal with cattle use ivermectin in liquid form that from my understanding gets poured onto the skin of cattle. This process exposes the one doing to pouring to the liquid, no fertility issues but coincidentally all that I have spoken to claim very strong immune systems with little downtime from colds/illnesses.