I got my vet to give me a scrip for COMFORTIS. Their fleas were gone - DEAD - starting in 45 minutes or so and all gone after 3-4 hours. I like this med for several reasons, one of which is that its smallest dose is for 5-10 lb. dogs, versus most of them that are for "less than 20 lbs.". 20 lbs. is overdosing by 4
It works VERY well.