The Best Flea Treatment for Dogs

Two dog afflictions always loomed in my consciousness when I lived in the lower 48 states: flea medicine and heartworm medicine. Each is costly but oh so necessary. Now that I live in Alaska, though, fleas aren’t as much of a problem to guard against as they were in California or Oklahoma. (Especially Oklahoma! So humid and hot — perfect for insects.) Still, I know a thing or two about the best flea treatment for dogs. From the little plastic applicators that you dab your dog’s back with to the newer chewables (so much more convenient, as long as your dog eats them!), I’ve seen it all.

A flea infestation can be disruptive and deeply annoying for your dog and family. The fleas will jump right from your dog to you, and soon everyone — and the entire house — will be infested! Not fun. Fleas thrive in warm conditions, but because of their longish life-cycles, they can continue to thrive indoors after summer ends.

If left untreated, a flea infestation can bring on more serious problems for your dog — for example, fleas are experts at adding extra parasites, like tapeworms, to your dog’s body. You definitely don’t want that!

How to spot fleas

Does your dog keep itching and scratching her entire body? Is she beginning to chew fur off random places? Do you notice dark specs in her coat? These are all signs of a flea infestation. An easy way to find out if fleas are infesting your dog is to look for flea poop, called flea dirt, in your dog’s coat. Comb your dog’s fur onto a piece of damp white paper. If the brown flecks stay brown, your dog’s just dirty. It’s time for a bath! If the flecks turn red, however, that means your dog has fleas. Fleas bite and suck your dog’s blood, and that blood passes into their fecal matter. Yuck! Time for some intervention.

Flea prevention

First, a little Flea Prevention 101: wash things regularly. Wash your dog’s bedding every week or two in the washing machine with hot water. Vacuum your carpets weekly, and your couches, and anywhere your dog hangs out. Fleas multiply very quickly, and their favorite place to do this is in those warm, fur-strewn places your dog loves to chill.

And of course, keep your dog shampooed! Every couple of weeks should do the trick in most situations. But if you go somewhere extra dirty, like a barnyard, and your dog rolls around in mud, go ahead and give an early bath.

The very best way to keep fleas off your dog, though, is to use flea treatment before fleas ever find your dog’s furry body.

Here are our favorite flea treatments for dogs. There’s something here for every budget!

K9 Advantix

K9 Advantix is a memorable brand because of its adorable TV ads. At least, I always found the ads super cute, with the happy, flea-free puppies running through tall grasses. I used K9 Advantix with Bella when we lived in hot southern California. Was it expensive? Kind of. But it was so worth it; all summer, we dealt with searing heat. Bella spent a lot of time inside or outside lying under shady lemon and grapefruit trees. (Hint: fleas love shady, squish outdoor spots and squishy, soft indoor nooks, just like dogs). We dealt with skunks, but not with fleas, thanks to K9 Advantix. I always bought the 6-month supply, but if you live in a northern state like Montana, Idaho, or  Alaska, you probably won’t need six months’ worth of K9 Advantix. Thankfully, they offer it in 1, 2, 4, and 6-dose packs. The price goes down as the doses do, so definitely only get what you need. Of course, if you live in a hot, year-round humid state in the south, you’ll probably need at least six months’ worth of the stuff.

Here’s how K9 Advantix works: it’s the little plastic applicator tube of anti-flea medication that you apply two or three times along your dog’s backbone area and down to the base of her tail. It contains three active ingredients: imidacloprid and permethrin, which kill parasites that are already on your dog (if there are any) by shutting down their central nervous system, and pyriproxyfen, which halts parasite development so they can never mature enough to reproduce. Each dose keeps fleas away for a month (hence the monthly dosage) and kills existing fleas within 12 hours.

In addition to keeping fleas away, K9 Advantix II kills ticks, mosquitos (something other popular brands doesn’t offer), lice, and biting flies.

On Amazon, this one’s available for large and extra-large dogs.

Frontline Plus for Dogs

Because we usually ended up using whatever flea medication Costco was selling at the moment, we often used Frontline Plus on our dogs. This one doesn’t protect against mosquitos, but it does repel and kill fleas, flea eggs and larvae, lice, and ticks — including ticks that can carry Lyme disease. Like K9 Advantix, it’s waterproof. Unlike K9 Advantix, it comes in an 8-month pack. You can split it between two summers or, if you live somewhere hot and humid like Oklahoma — where we used Frontline Plus for much of the year with our German shepherd, Bella — you can use it during the warmer summer, fall, and spring months.

The link below will take you to a page where you can choose the right dosage for dogs from 0-22 pounds, 23-44 pounds, 45-88 pounds, and 89-132 pounds. Like K9 Advantix, this is not a cheap flea treatment, but it does the job well. Plus, it’s much less expensive on Amazon than it is at local pet stores or even Costco — while still being a genuine product (if you follow this specific link! We’ve sniffed out potential counterfeits and blocked them from our list).

Hartz UltraGuard Plus Flea and Tick Spray

Since we rarely have warm summers — last summer was a terribly hot exception — not many Alaskans give their dogs flea medicine. But we do like to keep Hartz UltraGuard Plus Flea and Tick Spray around and spray it on Eira when it gets warm. It kills fleas and ticks on contact and lasts for up to a week, while keeping flea eggs from hatching, thus preventing re-infestation, for up to a month. A huge plus is that it’s wildly less expensive than a true flea medication like Frontline or K9 Advantix. If you live in a hot, muggy area, I’d use this together with the stronger flea medications, however. It’s the perfect spray for your dog’s bed, the couch, and even outdoor spaces if you suspect they’ve been infested with fleas.


We love this flea and tick spray from Hartz! 

Before trying it for the first time, I let Eira have a sniff…


Eira sniffs the aloe-containing flea and tick spray!

…so that she’d let me spray it on her coat. Which kind of worked.


It was easier when I wasn’t trying to get a photo of the spray! 

Even though it had gotten cold in Alaska a couple weeks ago, the weather turned warmish and soggy with rain. So I’ve been spraying Eira with this trusty stuff, and she remains flea-free (and tick-free, too).

Seresto Flea and Tick Collar

Some people haven’t found the chewables, liquid applicators, or sprays to work too well — but it’s almost unanimous that flea collars work amazingly well. And they’re more expensive because of that. But they’re worth the price! The Seresto flea and tick collar works by slowly releasing imidacloprid and flumethrin, two flea-killing agents, throughout your dog’s entire body in small, safe amounts over a long period of time. The collar is effective for 8 months as long as you only bathe your dog once a month. If they swim or bathe more than this, the collar is still effective but only until 5 months for fleas or 7 for ticks.

Capstar Fast-Acting Oral Flea Treatment for Dogs

If your dog’s been infested with fleas and you want them gone NOW, Capstar Fast-Acting Oral Flea Treatment for Dogs is exactly what you need. One oral pill starts killing fleas half an hour after you give it to your dog! How’s that for fast? Four hours later, every single flea on your dog will be dead. You’ll have to do some serious sweeping around the area, after which you should spray it down with Hartz, whether it’s outside or indoors. Then put a flea collar on your dog or start him on a long-term flea and tick medication! The Capstar oral flea treatment is best for immediate, emergency use. If needed, you can use both Capstar and Frontline or K9 Advantix together safely.

With the right flea treatment for your dog, you and your pup can enjoy tons of hours of outside and indoor play without worrying about parasites.


Eira, gleefully free of fleas, runs along the tall grasses of our backyard.