Save Up To 40% Off For Fipnil. And more Fipnil Flea Treatment: Fipnil dog flea treatment is specially developed to effectively kill dog fleas and ticks. The treatment effectively prevents new flea and tick infestation for up to four weeks. It kills most fleas and ticks within the first 48 hours and the more resilient ones within one week. The medication is available for small dogs, puppies, medium dogs, and extra large dogs.