Ermagahd - not math! Math and I don't get along. Surely SOMEONE out there has calculated "if I add X ml to Y ounces of water, the dosage is Z ml per average 6 lb bird", or something to that effect. Anyone?
I happen to have a 10 ml pipet and a 100 ml volumetric flask as well as 1 ml and 3 ml syringes so it's rather simple for me to do the dilutions.
There is no avoiding the math to get it right.
You need a scale to weigh your birds.
You will need the 1 and 3 mls graduated syringes.
You can dilute 6 mls of the Safeguard goat dewormer (shake it vigorously prior to measuring out the 6 mls - using the 3 ml-syringe) and dilute it into exactly 4 oz of clean water. This will give you a 5 mg/ml solution of fenbendazole.
To calculate how much to give each bird, weigh them in pounds and multiply by 0.68. That will tell you how many mg they need. Let's call this number X.
Then take X and divide by 5 to tell you how many mls you need to give the bird.
Say you have a 6 pound bird. You will multiply 5 by 0.68 to get 4.08 mg.
Divide 4.08 by 5 and you get 0.82 mls of the solution you made. Every day. For 12 consecutive days.
I used tiny pieces of bread, soaked the bread with the dose and fed to the bird keeping the rest of the chickens from stealing it. It is very time consuming if you have even a small flock like mine.