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The essentials

  • Flea shampoos contain pyrethrin — This is the active ingredient meant to eliminate fleas, however, it only targets adults and eggs, leaving larvae and pupae behind.
  • Fleas are becoming resistant to many shampoos — Parasites like fleas can develop a tolerance to certain ingredients in flea shampoos, rendering them ineffective.
  • Maintenance is important — Keeping your home clean and your pet well-groomed is key to avoiding these pests.

Why we don’t recommend flea shampoos for dogs 

Our vets believe that shampoos aren’t effective at eliminating fleas. This is because the chemicals in these shampoos only eliminate fleas at a particular point in their life cycle. They don’t kill flea larvae or pupae, meaning it’s only a matter of time until remaining eggs turn into adult fleas.

Instead, our vets recommend an oral medication capable of killing all types of fleas at every point in their life cycle. Simparica, Bravecto, and Nexgard are a few of our favorites. That said, these options do require a written prescription to purchase.

Ingredients to avoid

In addition to their ineffectiveness, flea shampoos can also contain some pretty harmful ingredients. Below are a just a few of the additives in flea shampoos that make our vets advise against them:

  • Pyrethrin. Most flea shampoos contain pyrethrin, a harsh chemical that’s extremely toxic to cats and fish. A lot of products feature both dogs and cats on the packaging and don’t explicitly say not to use them on your feline. Though rare, dogs with skin sensitivities may also have a reaction to this chemical.
  • Essential oils. Depending on the concentration, essential oils can be extremely harmful to both dogs and cats. According to Pet Poison Helpline, the most dangerous essential oils for dogs are tea tree oil, pennyroyal, wintergreen oil, and pine oil.
  • Citrus oil extracts. Citrus oil extracts like limonene and linalool are used in flea shampoos and can cause allergic reactions in some pets, though this issue is most common in cats.

👉 If you’re going to use a flea or tick shampoo on your dog, look for an option with an insect growth regulator. Without this, a flea treatment won’t truly address your pet’s infestation.

The potential for side effects

According to UC Davis, it’s possible but rare for pets to experience allergic reactions and adverse side effects after using a flea and tick product. Some potential side effects include vomiting, diarrhea, drooling, and other irregular behaviors. If this happens to your pet shortly after applying a flea treatment, wash it off immediately and take your dog to the vet. In some cases, these side effects don’t appear until a few days after the treatment. Always consult with your vet if you think your pet is having an allergic reaction.

Dog flea shampoo alternatives

If you’re interested in a safe alternative to flea shampoos, look no further. Below are a few vet-recommended solutions to try instead:

  • Prescription remedies. If a prescription is required, your vet will be able to provide a recommendation. In some cases, the medication is sold in vet offices.
  • Dish soap and a comb. When it comes to young puppies and kittens, most vets recommend a flea comb and a gentle dish soap like Dawn.
  • Over-the-counter solutions. Capstar is one example that starts to kill fleas within 30 minutes of applying it to your pup.

How to use a flea comb on your pup

Follow our recommendations, and your dog’s fleas won’t be back any time soon:

Don’t brush your dog indoors — Fleas and flea eggs can fall out of your dog’s fur and burrow into your carpet and furniture. It’s always best to comb your pet outside or in the bathtub so you can keep any parasites on your pet contained.

Focus on problem areas — Fleas hide in certain areas on most dogs, most commonly around the abdomen, neck, ears, tail, and lower back. Comb through these spots a few times each before moving on.

Brush in one direction — For best results, start at your dog’s head and work toward their tail.

Clean out the brush as you go — Fleas and their eggs can get trapped in the comb’s teeth as you work. Every so often, make sure to wipe the comb on a damp paper towel to avoid introducing eggs back into your dog’s fur.

Reward your pup with a treat — Giving your pup treats as you work will help them stay put during this process, which, depending on your dog’s size, could take quite a bit of time.

Prevention is the best medicine

When it comes to fleas, get ahead of the problem. Topical flea and tick preventatives like Frontline, K9 Advantix II, and Effitix are good over-the-counter options. However, you shouldn’t rely solely on these products since fleas are becoming increasingly resistant to these medications.

👉 For more options, check out our full list of vet-recommended flea preventatives.

How to protect your dog during flea and tick season 

While prevention is best, there’s a host of other steps you can take to help protect your pup. Below are some of our favs:

Bathe your pup regularly — Keeping your pet clean by bathing them at home or the groomers can help protect your pet from fleas. In addition, regular baths can help you find and treat any pests long before you have an infestation.

Avoid wooded areas during peak seasons — Fleas thrive in wooded brush or sand and are most active during the spring and summer. However, if you live in a warmer climate, they can be an issue year-round. This map is a helpful resource that tracks the prevalence of flea- and tick-borne illnesses in your area.

Wash your dog’s bedding frequently — If you’re currently dealing with a flea infestation, wash your dog’s bedding every day with hot water. Even without an outbreak, it’s best to keep your pup’s bed clean by washing it once a week.

Vacuum a couple of times a week — Fleas can hide in fabrics and carpet fibers, so keep on top of vacuuming (as often as every day!) and pay special attention to carpeted areas and couch cushions.

Try a flea and tick yard spray — Outdoor insecticides are a great tool to limit your pet’s exposure to unwanted bugs. Our list of favorite sprays are completely safe for your animals and your lawn.

Frequently asked questions

Are dog flea shampoos safe?

Not usually. Our vets don’t recommend using flea shampoos because they’re ineffective and tend to contain some pretty harmful ingredients.

Are dog flea shampoos effective?

No. Since they don’t target the full life cycle of fleas, using a flea shampoo alone won’t completely rid your dog of these pesky parasites.

What’s the most effective flea shampoo for dogs?

Rather than a shampoo, our vets recommend using topical treatments or oral medications to get rid of fleas completely.

What shampoo do vets use on dogs for fleas?

Our vets don’t recommend using flea shampoo on dogs.

What flea shampoo kills fleas instantly?

Most flea shampoos kill adult fleas as well as eggs but miss larvae and pupae. An over-the-counter product like Capstar can be effective and kills fleas in 24 hours.