[matese]

I suggest consulting your vet. Since Sentinel will not keep fleas off your baby I would mention this to your vet, tell your vet you want something that will kill fleas not just make the fleas sterile. And check about using topicals like frontline and Advantage on a 2.5 Lb pup. Even using topicals fleas and ticks will get on the dog, they have to bite the dog, ingest the blood of the dog in order to die. Keeping dogs off grass and away from leaves and trees can help preventing fleas and ticks getting on dogs. Speak to your vet, what works for one dog does not mean it will work for all dogs. And at 2.5 Lb you have to be very careful to not over medicate.