My dad said he'd sprayed more lambs' feet for scald this year than he could remember!
What did you see when you looked at them? Were they a bit soft and maybe pink between the two bits of hoof? Or sore where the hoof meets the leg, at the top?
How old are your lambs? Did their feet need trimming? What's the weather been like? (sorry, loads of questions, just helps to understand why it's going on)