Q: What should we know when it comes to controlling fleas on our dog and cats?

A: Fleas are truly the kind of creatures that give parasites their bad name. Despite the fact that Americans spend something like $9 billion annually fighting them, fleas are extremely adept at torturing us and our pets. When I first started in veterinary medicine almost 40 years ago, flea control products were crude, overly toxic and not very effective. Over the years, the old flea collars, sprays and powders have been replaced by an evolving arsenal of products that are safer for pets, humans and the environment, and much more effective.


The pet-care industry newsletter Veterinary Practice News published an interesting article earlier this year discussing how manufacturers evaluate the efficiency and safety of their flea-control products by analyzing information collected from parasitology researchers, veterinarians and pet owners. Dr. Michael Dryden, a professor of veterinary parasitology at Kansas State University's College of Veterinary Medicine, investigates the industry's most popular flea and tick products, including Advantage, Capstar, Comfortis, Frontline Plus, K9 Advantix, Program, Promeris and Revolution. His projects include lab evaluations and field studies.

Dryden calls Tampa, Fla., a "flea capital," where vets and pet owners are skeptical about whether any flea-control products actually do the job. "We used Frontline," he says, "in homes where pet owners claimed they had been compliant with the various products they'd used to rid pets of fleas, and we had success getting rid of fleas 100 percent of the time." Dryden says certain regions have more flea problems than others, but climate is only one factor.

It's no surprise that some fleas are more resistant to insecticides (survival of the fittest), but that doesn't mean they're immune. According to Dryden, even the toughest fleas will eventually be killed by the products he's investigated, though it may take two or three months to control an existing infestation.

"Prevention is always the better plan," Dryden says, "but too often pet owners don't invest in products until they see fleas in their homes or on their pets."

Dryden's team, nicknamed "Flea CSI," has found that some pet owners admit that finances prevented them from using the products as directed. Others reduced their effectiveness by applying them incorrectly, or bathing pets or letting them swim frequently without reapplication. "Clients with an elevated deck or porch that allows access to flea-infested animals means flea eggs will constantly be redeposited in the environment, which is another factor affecting control."

Effective flea control means not only getting rid of an existing infestation but preventing re-infestation.

That's why Dryden recommends ongoing prevention efforts as the best hope for flea-free pets.

Pet owners have more choices than in the past, some of which are available only by prescription while others can be purchased at pet supply stores or online catalogs. Some products combine flea control with heartworm prevention. Some are given in pill form, while many are applied to your pet's skin as a topical ointment. Whatever you choose, experts typically recommend a comprehensive control program, which kills adult fleas as well as interfering with growth and reproduction.

Please be aware that some products approved for dogs are lethal for cats. Read the package carefully before applying the medications to your cat!

Your veterinarian also is a great source of information and guidance when it comes to choosing the products that will work well for you and your pet, and how best to use those products.

David Tayman, D.V.M., has practiced veterinary medicine in Howard County since 1974. E-mail questions to Dr. Tayman at David.Tayman@vcahospitals.com.