I noticed that this year in Los Angeles, California fleas have developed a
resistance to Advantage. I then switched to Frontline and it worked. Perhaps
fleas in Florida have developed a resistance to Advantage? I suggest trying a
different brand. I really think these companies should change their formula
every year as fleas are becoming resistant.

Get a batch from your vet.  The internet stuff could definately be
counterfit.  Also, treat the environment.  Use a spray or bomb with an
insect growth regulator.  Vacuum daily and throw away the bag.

Frontline needs to be applied directly to the skin to be effective.  If you
spill too much of it into the fur, it won't work very well.  Advantage works
exactly the same way (same formula).

Your home/cats' environment might also be infested.  Frontline doesn't kill
flea eggs or larvae, so if the cats sleep or lie where there are flea eggs
or larvae - they'll become infested again and the cycle begins again until
those fleas die off.  This could give the appearance of the drug losing
efficacy.

Also, are your cats exposed to other cats or dogs or possibly infested
environments?  If so, you could have a reinfestation problem.

Treating the cat is only one part of getting rid of fleas.  You need to
treat the environment, too, and also prevent reinfestation.

Good luck.

Phil

    What Frontline (and other top spots) does is kill fleas after
they bite and if they don't die immediately, the secondary sterility
ingredients kick in.  These usually work by either preventing the
development of chitin (which young fleas need to have to break out of
their eggs) or by using an insect growth regulator that prevents
larvae and eggs from maturing.
    What a lot of people forget is that if you see fleas on your
pet, you've got fleas in your house.  And you've got hundreds of them
in your house, in the carpet, on pet beds, probably even in *your*
bed.  The species we call 'dog fleas' prefer to drink dog blood, will
drink cat blood, and don't like human blood.  The species called 'cat
fleas' will bite humans (and cats and dogs and pigs and civets and
just about anything else).  
    Female fleas lay 16-20 eggs per day -- around 600 in their
lifetime, and the population of fleas is generally 50% eggs, 30%
pupae, 15% larvae, and 5% biting adults.  You have to kill all the
fleas, not just the biting adults.
      To get rid of fleas you generally need a two step approach --
treat the pet and the environment.  Flea eggs are extremely tiny and
collect wherever a pet sleeps.  They hatch and turn into larvae, which
do not suck blood.  Larvae eat the pre-digested blood that makes up
flea dirt, and go into a cocoon.  They stay in the cocoon for five to
fourteen days.  At the end of that time they can emerge, or they can
stay in the cocoon for 2-3 months until they detect vibration,
pressure, heat, noise, or carbon dioxide (all of which signal a nearby
blood source).  You can get rid of fleas just using Frontline, but it
will take longer than treating the environment as well as using the
topspot.

Orchid
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