I’ve used Frontline flea killer for years & loved it til now. Have the fleas become resistant?
I have two dogs who are mainly outside dogs. I used frontline and they come in and out as they please with no fleas. Last month I noticed that I had flea bites on my feet, so I checked the dogs and sure enough they have fleas. I reapplied and waited, three weeks later they are still infested. I applied it again, and still the fleas survive. Have the fleas become resistant? Is there a refund available?