Have you checked the Bob Martin powder is safe to use on young puppies? If it is, I don't imagine it will be any where near as effective as the modern preparations like Frontline - these have the advantage that you only need to spray the dog every few months (ie long lasting protection) If your puppy does have fleas, then eggs will have been laid in your house, on carpets etc so you need also to buy a spray to treat the house eg Acclaim (again available from your vet) If you don't treat your carpets etc, the eggs will hatch out & the whole cycle will begin again.
Fleas aren't dangerous as such but they can cause dogs/cats intense irritation, resulting in frequent scratching which can lead to skin infections. Some dogs are also allergic to flea saliva which can result in severe skin problems. Fleas are also hosts for the tapeworm, another reason to make sure your puppy is treated for fleas & also wormed correctly (your vet will supply you with effective wormers)
