How Many Fleas on a Dog Is Considered an Infestation?

Stephanie Dube Dwilson

Even one flea on your dog could cause itching and scratching. But how many fleas on a dog is considered an infestation? Although there's no particular number that indicates an infestation, even a few fleas could signify there are many more hiding in your dog's fur and your home. With fleas, it's better to take action sooner rather than later.

Just One Flea Can Be a Sign of a Problem

If you see just a few fleas on your dog, you may be tempted to think it's not a big deal. Although the random flea might show up if you've just taken your pup for a walk, more than one or two could be a sign of a problem. As few as 20 fleas might mean your pet is infested, while the most could be between 200 to 300. 1

Ignoring a few fleas can quickly lead to an infestation on your dog and in your home,because two adult fleas could lead to hundreds of eggs and pupae. Fleas start feeding on blood within minutes of landing on your pet. Then they mate, and a female can start laying eggs within two days.3 In just four to nine days, she will lay 27 eggs or more each day in your dog's fur. The eggs can fall off into your carpet and other places. Larvae can hatch from the eggs five to eleven days later, then grow into pupae within tiny cocoons. They can stay in a cocoon for weeks or even months. The pupae are the hardest to kill, so it's a good idea to treat the fleas before they reach this stage. This is another reason why acting right away is so important.

Signs Your Pet Has Fleas

There are many signs that your dog has fleas. The most obvious is if your dog is itching and scratching more than normal. You might also see tiny black specks (called flea dirt) in his fur or bedding. Flea dirt can turn a dark red-brown color when sprinkled with a little water.

Running a flea comb through your dog's fur can also reveal fleas. Tiny white segments that look like grains of rice where your dog sleeps or sits are tapeworms, which is another sign of fleas.

Treating Your Pet

If your dog has fleas, it's a good idea to talk to your veterinarian about your best options. Your veterinarian might recommend a pill that kills all the adult fleas on your pet. You can also use a flea shampoo to attack the little bugs head on. Adams Flea & Tick Cleansing Shampoo kills adult fleas and prevents eggs from hatching for 30 days. The Adams Flea & Tick Collar Plus for Dogs and Puppies can protect your pup for up to six months. This is especially helpful if you let your dog go outside a lot.

Treating Your Home and Yard

Treating only your pet isn't enough. If you don't treat your home and yard too, the infestation will continue. Fleas can live a long time and might survive long enough to reinfest your dog later.

If your home has fleas, you should vacuum the house and wash your bedding as well as your pet's. But don't stop there. Adams Flea & Tick Home Spray kills both fleas and ticks. It protects for up to seven months and also kills roaches, spiders, ants, and more. The Adams Flea & Tick Carpet Powder kills fleas, eggs, larvae, and pupae. Each package treats one to two rooms (200 to 400 square feet). The powder also has an insect growth regulator that kills fleas for up to 30 days and controls reinfestation for up to 365 days.

For the yard, try Adams Yard and Garden Spray. It protects from fleas for up to four weeks and also kills ticks, mosquitoes, and ants.

Prevention Is Important

Although you should treat fleas if you see any, prevention is important too. If you can stop fleas from invading your home and yard in the first place, you won't have to worry about an infestation. Once you get the problem under control, continue treating for fleas, even in the winter.

Seeing even a couple of fleas on your dog can be a sign that an infestation is underfoot. If you spot a few, run a flea comb through your dog's fur to see if there are more. If you treat your dog, your home, and your yard right away, you should be able to avoid a major infestation down the road.

1. Flea Science. "How Many Fleas Can Live on a Cat or Dog.",

2. Potter, Michael F. "Flea Control and Prevention." Entomology at the University of Kentucky, June 2018,

3. Merchant, Mike and Robinson, James. "Controlling Fleas." Texas A&M AgriLife Extension,

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