Dog and Cat Fleas: Pour-on Products to Kill Fleas
Dr. Debra Primovic
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. Use products ONLY as directed.
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 In the past, sprays, powders, dips, and shampoos were very popular but have largely been replaced by the more effective and environmentally friendlier oral and spot-on treatments.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:
Never apply dog flea medication to a cat!
Apply medication to an area where your pet can't reach to lick.
Use the product recommended for the weight of your pet.
Do not combine flea products unless instructed by your veterinarian. Incorrect combinations can cause toxicity!
If you use over-the-counter medications, use only as directed. Take very special care to monitor cats and small dogs for 24 hours after administration if using a product containing permethrin or pyrethrin.
Additional Flea Control Tips:
It is best to prevent fleas than to treat active infestations.
Repeat treatments are necessary to kill new fleas that jump on your pet and to kill the different stages of the flea as they develop in your home and yard.
For monthly products, keep a reminder system. Try giving medications the same day of every month. Place the reminder in your calendar or on your refrigerator.
If your pet's a swimmer or bathed frequently, consider "waterproof" products such as Frontline Plus® or Revolution®, or "water-resistant" products such as K-9Advantix® or Advantage®.
If your pet gets wet or is bathed and the product is not waterproof, you may need to reapply to obtain full protection.
Even for water-proof products, it is often recommended not to bathe your dog for three days before or three days after applying medications. Follow manufacturer's recommendations.
If you live in a warm climate, most veterinarians recommend year-round flea prevention.
Some flea control products are combined with heartworm prevention medications, tick control medications, and other gastrointestinal parasite control. Talk to your vet about which product might be best for your pet.
If you have an active infestation, using products that kills adult fleas and interrupt develop of new fleas is ideal. Some products do both or you can use two different products, but you should never use more than one product without consulting your veterinarian as toxicity could result.