The best places to look for fleas on your pet are the base of the tail, stomach and groin regions, and around the face and ears. Sometimes no fleas are found but only tiny, black granules that resemble black pepper. This material is flea feces or flea-dirt and consists of digested blood. To distinguish this material from dirt, smudge it on white paper and add a drop of water to it. If you see a reddish-brown color, your pet has fleas, even if you cannot find a live one.
Fleas are more prevalent outdoors in warm weather. Usually dormant fleas hatch after thirty days of warm weather outside. However, as long as there is a host animal, fleas can live throughout the year indoors. After feeding on an animal, fleas drop off the animal and deposit their eggs in cracks, crevices and carpeting. A single breeding pair of fleas may produce 20,000 fleas in three months. After two to twelve days, eggs hatch into larvae that feed in the environment. Larvae molt two times and then older larvae spin a cocoon in which they remain for one week to one year. The long period during which the larvae remain in the cocoon explains why fleas are difficult to eradicate from the environment. A hungry adult flea finally emerges from the cocoon.
Many different products are available for flea control. To eradicate fleas, you must apply the insecticide correctly and at time proper intervals. All pets and the environment itself should be treated to eradicate fleas. Traditionally, the products we used for our pets were pyrethrin or permethrin based spays, powders, and dips. These products had to be reapplied frequently, had very little residual value, and could be dangerous for cats and very young or old dogs. Treatment of the environment with insecticide sprays and bombs was essential to controlling flea populations. Some pets with skin allergies were actually allergic to the pyrethrins. In addition, fleas rapidly developed resistance to these chemicals.
Today, there is a new generation of topical, long lasting flea control. Products like fipronil (Frontline) and imidacloprid (Advantage) are more effective products, with more consistent residual action, and actually a higher safety margin than older flea products. These products are easy to apply and we recommend using them monthly during flea season (April or May until November or December). Frontline also provides protection from ticks when used monthly.
For owners who want to avoid topical pesticides on their pets, lufenuron (Sentinel and Program) are oral medications that limit the reproduction of fleas. These products work best for pets that are mostly in their own house and yard, because once the flea population is exposed to the medication, they die off, unable to reproduce. Pets can still get an occasional bite, but the medication will keep the environment from becoming infested.
Environmental treatments are less necessary today, but in a heavily infested home may beneficial. Sweeping and vacuuming, as well as washing bedding, are probably most helpful for removing flea eggs and larvae from the home. Following up with a household spray, ideally containing an insect growth regulator (IGR), should help eradicate the pests more quickly. Most household products need to be repeated in two to four weeks, according to manufacturers instructions. Finally, never use household products on pets or use a pet product on a pet it is not specifically labeled for. Be especially careful about the many DOG-ONLY over-the-counter products that can be deadly for cats. Also watch for minimum age requirements as well as warnings about sick or elderly pets.
Dr. Mary Welle is a Veterinarian at All Creature's Animal Hospital in Urbana, Illinois.
Return to Dr Welle's Wisdom
Return to Visit
Our Vets
