Good point - I'm sure you can overdose - but it's expensive and it's not as though you'll be dumping half the bottle in. The reason I was liberal is that it seems when adding to water and food, it's more likely the ducklings weren't getting enough, since water was constantly spilled and changed out when dirty. I wasn't able to get my duck to take a proper dose of straight vitamin B, so I added it liberally to the food and water in hopes that she would end up with enough. By liberally I mean maybe a tsp to food and same to water - and that was shared and spilled by all ducklings. If that makes sense. If you can get your duckling to swallow the proper dose, then i'm sure that's a better route.