Dog and Cat Fleas: Pour-on Products to Kill Fleas

Fleas are a nuisance that will be coming out in full force this spring. There are numerous treatments for fleas including pour-on, also called spot-on, medications. Pour-ons are topical medications that are applied to the skin, absorbed and work to kill fleas.

The flea is a small brown wingless insect that bites the skin of pets and siphons their blood. When the flea bites a pet, it injects small amounts of saliva into the skin that works to prevent blood clotting and allows them to better "siphon blood". Many pets live with fleas without problems and others are extremely bothered with "flea allergy dermatitis". Some pets are allergic to the flea saliva which can cause severe skin reactions.

It is helpful to understand a little about the flea life-cycle to determine the best way to control them. There are four stages to a flea life-cycle including the egg, larva, pupa and adult. The way the life-cycle works is an adult flea jumps on a pet where he sucks blood and breeds. The flea lays eggs while on the pet and the eggs drop into the environment, generally your yard or floor. The eggs hatch in the carpet or grass, turn into larva, then pupa and eventually become adult fleas that jump back onto your pet. And the cycle repeats. This entire life cycle can take place in as little as two weeks when the weather is warm and humid, to several months or even a year in cooler, less ideal conditions. An adult flea can lay hundreds of eggs in their short three-week lifetime. Because their life cycle is very short, it is easy for one flea to cause an infestation in a very short period of time. It is estimated that for every flea you see on a pet, there are 200 additional life-stage forms buried in your house or yard just waiting to become adults.

Several new flea control products have come on the market in recent years. In the past, sprays, powders, dips, and shampoos were very popular but have largely been replaced by the more effective and environmentally friendlier oral and spot-on treatments.

Products vary in their active ingredients, safety, and methods of administrations. The various ingredients work on different parts of the flea life-cycle. Some kill adult fleas and others alter egg development. Some products are over-the-counter (OTC) and others are prescription only. Products can come in oral or topical forms. For many, the easiest products are the topical medications.

The topical or "spot-on" products are applied to your pet's skin between the shoulder blades. The medication is absorbed through the skin and distributed throughout the body.

Spot-on products include imidacloprid (Advantage®), fipronil (Frontline®), fipronil combined with methoprene (Frontline Plus®) and selamectin (Revolution®). Since Revolution® also contains heartworm preventative, it is available only by prescription or through your veterinarian's office. These products are generally safe and effective and can be obtained from most veterinary clinics and online. Some pet stores will also carry a smaller selection of available products. Uncommon side effects from topical products include local skin irritation and hypersalivation in some animals if licked when wet. Advantage® and Revolution® are used monthly and the Frontline products are applied every one to three months. Monthly applications of Frontline products are recommended for pets with flea allergies, heavy flea infestation levels, or those that require tick prevention and control.

There are also various other over-the-counter (OTC) medications available online and in pet stores. These products include Bio Spot® for Dogs (permethrin and pyriproxyfen), Bio Spot® for Cats® (etofenprox and pyriproxyfen), Zodiac Spot-on Plus® for Cats (etofenprox and methoprene IGR), and many others. The active ingredients vary. Some products contain a permethrin insecticide that can be toxic to some pets. These insecticides must be used with special care in small dogs and cats.

When it comes to fighting fleas, repeat treatments or monthly preventative medications are recommended. Routine administrations help to treat current fleas and prevent new infestations.

With all the products on the market, the best way to choose a product is to consult with your veterinarian. They can help you decide on the best product for your pet's lifestyle and risk of exposure. Routine use of preventative products can control flea populations in your environment. It is much easier to control the population than to treat an active infestation. Flea control is an important part of your pets' overall health and comfort.

Safety Tips for "Pour On" Flea Medications:

Additional Flea Control Tips:

  • Product Name
  • Action
  • Rx or OTC
  • Frecuency of Administration
  • Notes
  • Imidacloprid (Advantage®)
  • Prevents and kills fleas.
  • Available both as Rx and OTC.
  • Recommended monthly application.
  • Water-resistant. For dogs over 7 weeks and cats over 8 weeks of age.
  • Fipronil
  • \
  • (Frontline Top Spot®)
  • Kills adult fleas and ticks.
  • Available both as Rx and OTC.
  • Recommended application monthly for flea and tick control. May use every 1 to 3 months for flea control only.
  • Waterproof. For dogs and cats over 8 weeks.
  • Fipronil combined with methoprene
  • \
  • (Frontline-Plus®)
  • Prevents all flea stages from developing and kills fleas and ticks.
  • Available both as Rx and OTC.
  • Recommended application monthly for flea and tick control. May use every 1 to 3 months for flea control only.
  • Waterproof. For dogs and cats over 8 weeks.
  • Selamectin (Revolution®)
  • Prevents heartworm disease, kills fleas and controls ear mites. Treats sarcoptic mange and tick infestations in dogs. Treats and controls hookworms and roundworms in cats.
  • Available as Rx only.
  • Recommended monthly application.
  • Waterproof. For dogs 6 weeks of age or older. For cats 8 weeks of age or older.
  • Product Name
  • Action
  • Rx or OTC
  • Frecuency of Administration
  • Notes
  • Permethrin
  • \
  • combined with imidacloprid
  • \
  • K9Advantix®
  • Prevents and kills fleas, ticks and mosquitoes.
  • Available both as Rx and OTC.
  • Recommended monthly application.
  • Waterproof. Water-resistant. For dogs 7 weeks and older.
  • Permethrin
  • \
  • combined with pyriproxyfen
  • \
  • Bio Spot for Dogs®
  • Prevents and kills fleas, ticks and mosquitoes.
  • Available as OTC.
  • Recommended monthly application.
  • Re-application may be necessary after shampooing.
  • Ethofenprox combined with pyriproxyfen
  • \
  • Bio Spot® for Cats and Ferrets
  • Spot-on product prevents development of juvenile fleas and flea eggs for up to 3 months.
  • Available as OTC.
  • Re-application every 3 months with spot-on product. Use of towlette product every 3 weeks.
  • \
  • endcell}
  • Re-application may be necessary after shampooing.
  • Etofenprox and methoprene
  • \
  • Zodiac® Spot-on Plus for Cats
  • Kills and repels fleas, ticks and mosquitoes.
  • Available as OTC.
  • Recommended monthly application.
  • May not be available in some states. endcell}

Permethrin should not be used in animals with known hypersensitivity or allergy to the drug. This drug should be avoided in geriatric or very ill or weak animals.

Permethrins should never be used in cats. Homes with cats that are known to groom dogs should not use this product.

For dogs 12 weeks and older.
Permethrin should not be used in animals with known hypersensitivity or allergy to the drug. This drug should be avoided in geriatric or very ill or weak animals. Homes with cats that are known to groom dogs should not use this product. Permethrins should never be used in cats.

May not be available in some states.

Additional use of Flea Halt!® (pyrethrin) towelettes eliminate adult fleas, deer ticks, and mosquitoes for up to 3 weeks.

For cats 12 weeks and older and ferrets 16 weeks and older.

For products containing pyrethrins, use with caution in cats.