Adult fleas are only 1-5% of the flea population. It's the adult fleas that do bloodsucking damage and spread tapeworms, so it's important to eliminate them; but at least 95% of the flea population exists as eggs, larvae, and pupae that hide in carpets and yards.
Treating all pets (and the environment) ensures the removal of smoldering flea reservoirs. You may have noticed your pet has a flea problem because pets with flea allergies scratch incessantly. Other pets can have fleas but if they are not allergic to them, they won't scratch obsessively. It's easy to assume that pets who aren't scratching don't have fleas, but that's not always so.
To remove the fleas from asymptomatic pets, treat all pets whether they are scratching or not.
No. Cats are not small dogs. Only use cat flea treatments on cats. Cats are much more sensitive to flea products than dogs are, and some flea treatments can be very harmful to them. Because the surface area of the cat is proportionately different than that of a dog—a cat requires a different level of preventative. Flea treatments are formulated based on size and physiology so cat treatments are the best and safest products to use for cats. The single biggest cause of all non-medicinal poisoning is using the wrong products on cats.
If you treat your dog with a permethrin-containing product, allow the solution to dry before reuniting the dog and cat.
If your pet is on a monthly flea preventative but you are still finding fleas, read our detailed guide on why your pet's flea medication may not be working. To summarize, there are 3 reasons a topical doesn't appear to work: application procedure, the pet's skin, the flea reservoir (environment and untreated pets).
From the number of categories of products, you can tell how serious the flea and tick problem is. For most pet parents, topical or oral treatments used monthly are the most convenient. Excellent products include Flea5X Plus for Dogs, Flea5X Plus for Cats, Frontline Plus, Advantage II.
When flea prevention efforts haven't been sufficient, powders, foggers, sprays can be used for home flea control treatments. These products kill adult fleas immediately. You can also kill fleas on your pet by using shampoos, sprays and dips.
Flea combs and shampoos are excellent products to use on geriatric pets and those that have lost enough blood to fleas to be anemic. Combs and shampoos are also useful for young puppies and kittens with immature nervous systems. Or, prevent puppies and kittens from ever having fleas by treating the mother and the whelping area before they arrive.
Generally, it is unwise to combine two flea treatments because pets are healthier with limited chemical exposure. When it is necessary to use more than one product on a pet, it's because there is a problem with environmental control measures inside and outside the home.