Can fleas become immune to Frontline?

Answer by  MsLizziebug (833)

No. If you are using frontline make sure it's Frontline Plus with insect growth regulator(IGA). That will stop the life cycle of the fleas. If you have a flea infestation you may have to apply Frontline several times. Fleas lay eggs everywhere and hatch in different cycles.

Answer by  dreamsweeper (85)

I have used Frontline for over six years, and I have found it to be quite effective. I believe that if applied correctly the effects are very beneficial. Frontline kills fleas by way of sterilization, it does not kill them right away. The long term affect, if used properly is the complete wipeout of fleas.

Answer by  Sabharish (1610)

Fleas are not immune to frontline. But it is advisory to use a frontline spray type to kill and stop breeding of fleas. Whenever you find traces of flea dirts and your dogs starts itching just spray the frontline and let it for 24 hours for full effect and then your dog is protected.

Answer by  lilian (397)

In theory, it's possible for fleas to become "immune" to Frontline since it's a pesticide. If it's the first month of treatment, then you must wait because it attacks all stages of the lifecycle. No fleas should exist by the end of the first month. Don't skip a month.