There are notches on the plunger according to weight. Each brand is different. The one I have is measured double compared to that brand. So I will squeeze out a bead and cut it in half....and mix it with honey.
Yeah but horses weigh a lot more than humans. I haven’t seen these syringes but I can envision what you are saying. I know the dose is calculated in mg/kg, and I suppose a newborn foal might use less than her mare, closer to that of a full grown human, thus the notches. Those notches probably help a lot with measuring. The thing is, different protocols for prevention vs treatment. Maybe not dramatically different.
The dose per weight is the same for a horse as a human. So a 1250 pound human would use the entire tube of the Durvet brand.
I’m about 200 pounds so I just took a ruler and marked the plunger into 6 different equal lengths and plunged it to the mark for each dose. As a preventative it was two doses spaced 48 hours apart to begin with and then a dose every two weeks.
By chance I had a physical a month after I started and my chronic low white blood count was even lower. I looked it up and that is a side effect of Ivermectin. No adverse physical issues. The low WBC is probably from something else, but in retrospect it may have been better to work with a doctor (online?) than trying to self medicate.