Vectra is dog only. Please use caution with products not intended for feline use. They do KNOW you have a cat right?
I recommend Advantage II flea control (over 9 lbs).
Frontline Plus is NOT what it used to be. I can't thumbs down or dissuade people from this product enough. It's terrible. You might have had good results in the past or think it's working, but I can only relate my horror story of living with fleas the last 18 months.
There's a lot of "rumor mongering" which works and which doesn't. Pet shop owners will hear stories of what works and what doesn't work. Let me tell you what doesn't work from my experience and that's Frontline Plus.
A flea is a flea, some mutants might be more resistant, but the result is a slower death but still death. That you have some sort of mutant flea where the chemical won't work is extremely unlikely.
I used Frontline Plus for a couple of years, especially between 6mo and 18mo of age when I was actively walking the boys once a week on harness. Never had any issues. I stopped using this for 3+ years when the boys were restricted to indoors only.
However, upon moving into the new house, I was unprepared for a flea infestation from dormant eggs and fleas. In less than two weeks, it was so bad that my boys were alternating hiding in a closet, under the bed or in a kitchen cabinet in order to "escape." They were also acting withdrawn, got worms, and I was getting bit as well.
I went back to Frontline Plus, even so far as to do TWO treatments per month, flea spraying the entire interior of the house every 3-4 weeks by a professional company, bought a brand new top of the line Dyson Animal vacuum ($$$) to use daily, and poured my free time into cleaning, cleaning, and more cleaning.
Nothing seemed to get rid of these bastards. I'm serious, after 3 months of fighting them nearly daily, I was completely unhinged mentally and PO'ed beyond belief. I sought compensation from the previous owners shortly after discovering the problem, however it's a you moved in, it's your problem now scenario. I brought them with me, which is total BS. When I moved in, the warning signs were there from homeowners who didn't control their animals. The carpets had to be re-cleaned, a downstairs closet aired out from being used as a cat urinal, tufts of carpet in certain spots being torn from tugged at constantly by claws, and they were growing pot which required a humid environment. Fast forward 4 more months, I finally got the problem under control but not eliminated. That's 8 months total for those keeping count.
Fast forward 4 more months, so a full year has gone by now, I would periodically get a bite on the hand or neck from close contact with one of the boys every couple of weeks prompting another 2 week cleaning marathon.
This is the #1 reason why I had to wait an additional year to pick up a Savannah, because until this problem was eliminated, I was not going to subject a multi-thousand dollar investment in a kitten to an active flea household.
That is until I picked up Advantage II. I swear, if I found the chemist that made this stuff, I would kiss them and/or give them a nice bottle of wine.
With a singular dose of Advantage II on both boys, within 48 hours, all flea feces disappeared from my white tile counter tops in kitchen, white tile counter tops in master bathroom, and on the white comforter where the boys slept with me.
Frontline Plus was simply ineffective. And yes, I was using the real Merial deal every time. Not only was I using the official Merial capsules, I found 18 month expired Frontline Plus that I still had in the cupboard was just as effective. It killed fleas on contact, but did not provide any lasting benefit.
Since that initial application I went 8 weeks of no activity of any kind. No marathon cleaning, no feces on the white counter tops or comforter, until a singular rogue bite in the kitchen reminded me it was time for a re-treatment.
The pro-Merial crowd could argue that Frontline Plus just took a long time to build up and become effective to which I reply, going from black spotted white comforter to feces-less in 48 hours was purely the work of Advantage II.
I owe the joy of becoming a Savannah parent to Advantage II.