
You need to weigh your pups in grams not pounds. I have electronic scales for weighing puppies and nothing else. At 14 days most of my pups only need
0.02ml but it is a very tiny breed. The doses are given for metric and I certainly wouldn't give my pups 0.5ml - I wouldn't take the risk. It is far easier to be accurate if you weigh in metric. I too, only do "old money", but I am pretty finicky about getting doses accurate. I have used Panacur 10% for years.
Also, I weigh each and every pup, and work out individual doses - and I'm sure that the whole litter doesn't weigh the same.