Actually Rx is 2x of horse at $1.50/dose and that would mean you have to get six doses out of one syringe of horse paste.
My Rx is $3/capsule from a compounding pharmacy. OTC should drop it below that.
I didn't have accurate info on the number of doses in the $40 (I think) prescription, which I assumed were less than the $5 animal tubes I got through a bulk purchase in mid-2020.