I have yet to try the horses--one of the ponies is very sick with liver problems and the vet said I should probably wait a little.
This bottle of ivomec Drench is sitting here by the computer begging to be used.
Can´t do it right now. I´ll try to later. Your pigs will be kind of oily if you do it topically.
The sheep drench you describe as having .8mg/cc can be used topically or orally.
Weigh your guinea pigs and apply behind the ears: 0.625 cc/kg
This will dose them at 0.5mg/kg (one cc contains 0.8mg ivermectin: 0.625 cc contains .5 mg ivermectin).
Weigh your pigs and use 0.25 cc/kg
This will dose them at 0.2 mg/kg (one cc contains 0.8 mg ivermectin: 0.25 cc contains 0.2 mg ivermectin).
Reread the ivermectin page if you need to.