Let's get this thread rollin:
I don't use LongRange. I use Eprinex which includes the same active parasiticide - eprinomectin. The difference between LR and Eprinex is. 1.) The pathway of administration. LR is injectable and Eprinex is topical. 2.) LR includes patented carriers that maintain a level of eprinomectin over a longer period of time. Here is the description of the carrier:
LONGRANGE® (eprinomectin) is a ready-to-use, sterile injectable preparation containing eprinomectin, a member of the macrocyclic lactone class of antiparasitics. Each mL of LONGRANGE contains 50 mg of eprinomectin in a co-solvent system of N-methyl-2-pyrrolidone (30% v/v) and triacetin (qs), along with 50 mg of poly-lactide-co-glycolic-acid 75:25 (PLGA), a polymer that allows a slow release of eprinomectin from the formulation, thereby maintaining a prolonged duration of product effectiveness. Butylated hydroxytoluene (0.2 mg/mL) acts as an antioxidant in the formulation.
I have had personal conversation with Dr. Steve Falk of Merial who developed LR. I was discussing Eprinex not LR. The only warning I recall on eprinomectin is that you should not treat your herd bull before turning him on cows as there is some reservations that eprinomectin might decrease spermatogenesis.
If there are fertility or conception issues with LR it could be in the "carrier".