fleas on dogs symptoms and prevention
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ChewyFlea & Tick / Health

How to Combat Fleas on Dogs: Signs, Treatment and Prevention

Does just the thought of fleas on your dogs and in your home make you itch? While these stealth bloodsuckers are unpleasant—and potentially dangerous—to live with, there are simple and effective ways to treat as well as prevent an invasion.

First, we must know our enemy.

What Are Fleas on Dogs?

“Fleas are tiny, wingless insects that survive by feeding on blood,” says Christine Cain, DVM, DACVD, assistant professor and section chief, dermatology and allergy at the University of Pennsylvania School of Veterinary Medicine in Philadelphia, Pennsylvania. “The most common flea in the U.S. that infests both cats and dogs is the cat flea, Ctenocephalides felis.”

These nuisance parasites can consume nearly 15 times their own body weight in blood per day, according to a study. And these prolific pests multiply rapidly, as a single female flea can lay up to 50 eggs per day.

Fleas experience a four-stage life cycle.

  1. Egg Stage: Each flea begins when the female lays white, oval eggs on a host, like a dog, after consuming the animal’s blood. The eggs are extremely tiny and very hard to see. As your dog moves, the eggs drop into his environment, such as the carpet, his bed and your sofa.
  2. Larva Stage: After 2-14 days, the fleas exit the eggs, hatching into worm-like larvae. The larvae eat flea dirt (the blood-filled feces adult fleas leave behind) for about 5-20 days before spinning a silk-like cocoon for their next stage.
  3. Pupa Stage: The pupa stage within the cocoon can take as little as a week or as much as several months, depending on the external conditions.
  4. Adult Stage: Finally, the adult flea emerges. Not wasting any time, fleas find a warm-blooded host, like your pooch, to feed from and the females repeat this cycle.

How to Spot Fleas on Dogs

“Signs that your dogs have fleas are the insects themselves or flea dirt, which is actually the feces of the flea,” says Meghan Solc, DVM, DACVD, a board-certified veterinary dermatologist at Dermatology for Animals in Akron, Ohio.

Flea dirt looks like tiny black flakes or ground pepper-like dots on your pet. You can perform a flea dirt test by applying a wet piece of paper on the suspected flea dirt. If it changes color to red or brown-reddish, it’s usually flea dirt.

“Most often we don’t see any of the signs but see the symptoms of flea allergy,” Solc says.

Common symptoms of any dog with fleas include:

  • Itching
  • Licking
  • Chewing
  • Scratching

Fleas often hide around your pooch’s tail, rear and belly because they are warm and protected there, Dr. Cain says. Highly sensitive dogs can be disturbed by even a single flea bite.

“Some dogs can have an allergic response to flea saliva, which can result in increased itch with exposure to fleas and subsequent flea bites,” Dr. Cain says. “This can result in self-induced hair loss, redness, crusts (scabs), hot spots and secondary skin infections, particularly around the back half of the body (rump, back of thighs, sometimes inner thighs), since fleas tend to hide in the dense hair coat around the rump of dogs.”

Learn more about allergies in dogs.

A simple way to check your pet is with a flea comb, like Safari's flea comb for dogs. Start combing around your pup’s ears and head and move toward the rump and tail. However, it’s common for pet parents to not see adult fleas while combing their dog even when fleas are present, Dr. Cain says. These pests are tiny and move quickly.

How to Get Rid of Fleas on Dogs

Once you find fleas on your dog, act fast. There are plenty of safe and effective products available for dogs of all ages and sizes.

First off, consult with your veterinarian.

“Most of the available products—including topicals, oral products or collars—are quite effective when used according to label instructions,” Dr. Cain says. “But pet parents should always consult their veterinarian before purchasing and using a product. The most effective choice often depends on the lifestyle of the dog, his environment and [any] concurrent health conditions.”

For example, she says if your dog spends a lot of time in the water, it can decrease the effectiveness of topical products. Also, if your household includes other types of pets, like cats, some topical products labeled for dogs might be toxic to them.

It is crucial to use flea control products consistently, as labeled, for the best and safest results, she adds.

“In some dogs, especially those with flea allergy, we may recommend more frequent use of flea control products or combinations of flea control,” Dr. Cain says.

Over-the-Counter Flea Medicine for Dogs

Flea Collars for Dogs

Active IngredientS:
Deltamethrin

Found in: Activyl Protector Band, Salvo Flea & Tick Collar, and ShieldTec Flea & Tick Collar

Targets: Fleas and ticks

Treatment frequency: 6 months

Age limit: 12 weeks or older

How it works: Kills fleas by disrupting nervous system function.

Imidacloprid, Flumethrin

Found in: Seresto 8 Month Flea & Tick Prevention Collar

Targets: Fleas and ticks

Treatment frequency: 8 months

Age limit: 7 weeks or older

How it works: Kills fleas by disrupting nervous system function.

Tetrachlorvinphos

Found in: Hartz UltraGuard Flea & Tick Collar, and Zodiac Flea & Tick Collar

Targets: Fleas and ticks

Treatment frequency: 7 months

Age limit: 12 weeks or older

How it works: Kills fleas by overstimulating the nervous system.

Tetrachlorvinphos, (S)-Methoprene

Found in: Hartz UltraGuard Pro Flea & Tick Collar, Hartz UltraGuard Plus Flea & Tick Collar, and Adams Plus Flea & Tick Collar

Targets: Fleas and ticks

Treatment frequency: 7 months

Age limit: 12 weeks or older (Hartz UltraGuard); 6 weeks or older (Adams Plus)

How it works: Tetrachlorvinphos kills fleas by overstimulating the nervous system. (S)-Methoprene is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction.

Topical Flea Medicine for Dogs

ACTIVE INGREDIENTS:
Cyphenothrin, Pyriproxyfen

Found in: Sentry Pro XFT Flea & Tick Squeeze-On

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 12 weeks or older

How it works: Cyphenothrin kills fleas by overstimulating the nervous system. Pyriproxyfen is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction.

Dinotefuran, Pyriproxyfen, Permethrin

Found in: Vectra 3D Flea & Tick Treatment

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Dinotefuran and Permethrin kill fleas by overstimulating the nervous system. Pyriproxyfen is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction.

Etofenprox, Pyriproxyfen

Found in: Sentry Pro Toy & Small Breed

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 12 weeks or older

How it works: Etofenprox kills fleas by overstimulating the nervous system. Pyriproxyfen is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction.

Etofenprox, Pyriproxyfen, (S)-Methoprene

Found in: Adams Plus Flea & Tick Spot On

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 12 weeks or older

How it works: Etofenprox kills fleas by overstimulating the nervous system. Pyriproxyfen and (S)-Methoprene are insect growth regulators that interfere with insect growth and development, thus preventing reproduction.

Fipronil

Found in: Sentry FiproGuard Flea & Tick Squeeze-On

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Fipronil kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system.

Fipronil, Cyphenothrin

Found in: Parastar Plus Flea & Tick Treatment

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 12 weeks or older

How it works: Fipronil kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system. Cyphenothrin kills fleas by overstimulating the nervous system.

Fipronil, Permethrin, Pyriproxyfen

Found in: Virbac EFFITIX Plus

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Fipronil kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system. Permethrin kills fleas by overstimulating the nervous system. Pyriproxyfen is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction.

Fipronil, (S)-Methoprene

Found in: Frontline Plus, Hartz Pet Defender Plus, Onguard, PetArmor Plus, and ZoGuard Plus Flea & Tick Treatment

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Fipronil kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system. (S)-Methoprene is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction.

Fipronil, (S)-Methoprene, Priproxyfen

Found in: Frontline Gold Flea & Tick Treatment

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Fipronil kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system. (S)-Methoprene and Priproxyfen are insect growth regulators that interfere with insect growth and development, thus preventing reproduction.

Indoxacarb

Found in: Activyl Flea Treatment

Targets: Fleas

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Indoxacarb uses the flea’s own enzymes to activate indoxacarb’s ability to kill adult fleas by paralyzing them and stopping eggs and larvae from developing.

Permethrin

Found in: Nutri-Vet K9 Defense Flea & Tick Treatment

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 12 weeks or older

How it works: Permethrin kills fleas by overstimulating the nervous system.

Permethrin, Pyriproxyfen

Found in: ShieldTec Plus Flea & Tick Treatment

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 12 weeks or older

How it works: Permethrin kills fleas by overstimulating the nervous system. Pyriproxyfen is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction.

Permethrin, (S)-Methoprene

Found in: Zodiac Spot On Flea & Tick Control

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 6 months or older

How it works: Permethrin kills fleas by overstimulating the nervous system. (S)-Methoprene is an insect growth regulator that interferes with insect growth and development, thus preventing reproduction

Chewable Flea Tablets

ACTIVE INGREDIENT:
Nitenpyram

Found in: Capstar Flea Tablets for Dogs

Target: Fleas

Treatment frequency: As prescribed by veterinarian

Age limit: 4 weeks or older

How it works: Kills fleas by overstimulating their immune systems.

Prescription Flea Medicine for Dogs

Topical Flea Medicine for Dogs

ACTIVE INGREDIENT:
Fluralaner

Found in: Bravecto Topical

Targets: Fleas

Treatment frequency: 12 weeks

Age limit: 6 months or older

How it works: Kills fleas by overstimulating their immune systems.

Imidacloprid, Moxidectin

Found in: Advantage Multi

Targets: Fleas

Treatment frequency: 30 days

Age limit: 7 weeks or older

How it works: Kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system.

Selamectin

Found in: Revolution Topical Solution

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 6 weeks or older

How it works: Kills adult fleas by disrupting their nervous systems; stops reproduction by preventing eggs from hatching.

Chewable Flea Tablets

ACTIVE INGREDIENT:
Afoxolaner

Found in: NexGard Chewable Tablets

Target: Fleas and ticks

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Kills fleas and ticks by overstimulating their immune systems.

Lotilaner

Found in: Credelio Chewable Tablet

Targets: Fleas

Treatment frequency: 30 days

Age limit: 8 weeks or older

How it works: Kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system.

Lufenuron , Milbemycin Oxime

Found in: Sentinel Flavor Tablets

Target: Fleas

Treatment frequency: 30 days

Age limit: 4 weeks or older

How it works: Lufenuron is an insect growth regulator or insect development inhibitor that interrupts the biosynthesis of chitin (which makes up their exoskeletons) in flea larvae but has no effect on adult fleas.

Sarolaner

Found in: Simparica Chewable Tablets

Targets: Fleas and ticks

Treatment frequency: 30 days

Age limit: 6 months or older

How it works: Kills fleas by inhibiting a key neurotransmitter in the pest’s central nervous system.

Spinosad

Found in: Comfortis Chewable Tablets, and Trifexis Chewable Tablets

Targets: Fleas

Treatment frequency: 30 days

Age limit: 14 weeks or older (Comfortis); 8 weeks or older (Trifexis)

How it works: Attacks the adult flea’s nervous system, causing rapid death.

Flea Treatments for Your Home

Only adult fleas live on pets, according to Dr. Cain. The immature fleas, which include the eggs, larvae and pupae, fall off our dogs and into our homes. She adds that you most likely will find the immature fleas in your pet’s sleeping or resting areas.

One helpful method of removing flea eggs is regular vacuuming. Just be sure to throw out the vacuum bag so the hatched pests cannot escape.

Pet parents also can apply environmental products, like Vet’s Best dog flea and tick home spray, to help kill the immature fleas around the home. They like to hide, so pay special attention to dark areas and along baseboards.

Note: When living with multiple animals, be sure to consult with your veterinarian before using environmental products. Some can be toxic to certain species.

Prevent Fleas on Dogs

It’s impossible to completely prevent exposure of your dog to fleas. However, experts agree that year-round use of effective flea control products like the ones listed above can go a long way.

“All animals can get fleas, no matter where they live, indoors or outdoors, if the yard is treated, if it's the winter, etc.,” Dr. Solc says. “The best way to prevent flea infection is continuing with year-round flea prevention.”

After all, it’s immensely easier to prevent a flea infestation than to have to treat one that already is established!

By: Sandy Chebat

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