Via Medicine registrations
You can add the arrival, end stock, return and loss of a drug.
As a start, add an ending stock on a certain date.
After that you can register and track supply, return and loss.
The use of the medicine is tracked when you enter the medicine and the used quantity under health.
In analysis & reporting, animal health, 04. medicine registration, you can see how much of the drug has been supplied, returned or lost. You can also see what the end stock is at this moment or any other period.