In a separate container, add 1 ml (cc) of the ivermectin and 30 ml of olive oil. Shake it up so that the ivermectin is mixed thoroughly. When you have made up this solution, give your dog 1.1 cc of this solution on the first of every month.
It is better to give him ivermectin directly into his mouth so that he does not spit it out/refuse it. Sometimes they will do that since the medication tastes bad.
Since you are in Georgia, I do want to advise you that there has been ivermectin resistant heartworm discovered in some places in the south. Talk to your local vet and find out if this is a problem where you live. If it is, one of the other products may be safer. They will, of course, be a lot more expensive.