Flea Control for Cats

Fleas are one of the most successful parasites on Earth, so they're a problem in many temperate climates. With over 2,500 species, it's no surprise than many of them want to feed on our feline friends. Dex P. writes:

Which flea & tick medicine do you think is best? There are so many out there. I have a few cats that can go outside, but most are indoors. Thank you!

Dex, we don't particularly care for any of the commercially available topical flea treatments because the chemicals used often have side effects, some of which can be disastrous for individual cats. There's just no way to know who will have a reaction and who won't.


We recommend trying a more organic approach first. If that doesn't work, you can always try more conventional attacks. Organic flea control is best achieved when the little nasties are attacked on multiple fronts.

First, you should make sure all the cats are healthy and are being fed a species-appropriate diet. Given a choice, fleas will be drawn to the least healthy hosts. See our top food recommendations here.


Next, use a flea comb to go through your cats' fur on a regular basis. To be most effective, slowly run the comb through their fur and then dip it into a glass of soapy water to clear it. If you find fleas, they'll end up in the water which you can then flush away.


You'll also need to address your entire home. Most experts estimate that only 10% of an infested home's flea population lives on pets. Fleas exist in three forms - as adults, larvae, and eggs. The adults will mostly be on your cat but the larvae and eggs can be anywhere. You'll need to vacuum your home at least once a week, focusing on your cat's hangouts and carpeted areas. Empty the vacuum into a bag and take it directly to the trash. You may not even see the eggs and larvae, but you'll be ridding your home of them with every vacuuming.


Finally, use a deterrent product like food grade diatomaceous earth directly on your entryways and under baseboards. We used to recommend dusting your cat's fur as well, but there is some risk from breathing the dust from DE. It's perfectly safe when it's settled.

Dex, we're confident that the organic approach can be just as effective as the chemical bombardment method in particular situations. However, it does take diligence and it works best before a major infestation takes place.


If you try the organic approach and find it isn't as effective as you'd like (believe us - we've been there), we recommend moving to an oral flea control medicine. We discourage the use of "spot-on" products as they've been shown to cause more harm than good for some felines. All of our suggestions in this section are based on our experience. You should always speak to a qualified veterinarian prior to administering ANY medication to your feline friends. 

It's best to start with the least harmful treatment, and in our opinion, that is Lufenuron. Lufenuron is birth control for fleas. It doesn't kill adult fleas, but will render them incapable of hatching viable offspring. It's administered orally in liquid form that must be given with food in order to be effective. It binds to fat molecules in the body so that fleas get a good dose every time they bite your cat. You have to choose the dosage based on your cat's weight in order to render an effective flea treatment. Be aware that Lufenuron can take as long as 30 days to become completely effective. During that time, you will need to continue the organic methods of combing and vacuuming. The original name for Lufenuron treatments was Program, but Program is no longer being made. Instead, Lufenuron can be obtained quite inexpensively from the fine folks at LittleCityDogs.com. Their Lufenuron treatments come in powdered form in small capsules. You can open each capsule and mix it with your cat's food or you can administer it as a pill. Whichever is easier.

You can also kill the adults through the use of an adult flea killer like Nitenpyram, AKA Capstar. Nitenpyram is a pill that is given orally and which kills 99% of the adult fleas currently biting a cat. It's effective for 24-48 hours, so it's a good choice if you're bringing a new cat into a flea-free home. It does have some side effects and can stimulate some cats in much the same way that nicotine effects humans. It's claimed to be safe for use over  and over again, but it's our opinion that it's best used as a one-shot, kill-em-all approach along with a longer-term treatment like Lufenuron. Nitenpyram is also available at LittleCityDogs.com.

The next step up the ladder in effectiveness is Spinosad, AKA Comfortis. This is a pill that is adminstered orally and which begins working within hours to kill both adult fleas and their eggs. Each pill renders 30 days worth of effectiveness against fleas. Unlike the previous drugs mentioned, Spinosad requires a prescription in the US.


Dex, we know how frustrating it can be for both you and your cats. Since your felines are allowed outside, we expect your final solution to be Spinosad tablets. If we can coax you to make your kitties, indoor-only cats, any of the methods outlined above can be effective, depending on the climate where you are. We wish you and your cats all the best!