We are currently in the thick of the worst flea season I have ever seen. October and November are typically the peak months for fleas, but this year the annual fall spike in fleas seems notably greater than usual.
Every spring the flea population in the environment consists of the relatively small number of adults that have been able to survive the winter. Once the weather warms those few start doing what fleas do best: eating and reproducing. Throughout the summer the flea population grows and grows and by the fall it is peaking, hitting the steeper part of it’s exponential growth curve. After last year’s very mild winter it is likely that the population got off to quite a head start, and it’s only becoming evident now how big the problem has become. In the past month I have seen dozens of pets not on a preventative medication with fleas, including half a dozen cases of strictly indoor cats with fleas, which is usually a rare occurrence.
Typically, the spread of fleas through the pet population occurs by the spreading of eggs, not by adult fleas jumping from one host to another. After feeding, the female flea becomes capable of reproducing. One female can lay over 5000 eggs in a lifetime, in batches of 20 or so. The eggs are laid on the host and then fall to the ground, within about 10 days the eggs hatch into larvae. The larvae will eat any available organic debris and after five to 12 more days will spin a silk cocoon and develop into pupa. The pupa is the most resilient stage in the flea life cycle. The cocoon itself becomes sticky, allowing it be covered and camouflaged with debris. If the conditions are ideal, the pupa can hatch as an adult in about one to two weeks, however if the conditions are not perfect, the pupa can hold off hatching for months. The pupa actually waits for certain stimuli such as warmth, vibration and an increase in carbon dioxide concentrations to indicate the presence of a new host before hatching. Once hatched, the adult will look for a blood meal. If an adult flea does not find a host to feed on, it cannot reproduce and will only survive for about a week. Once it finds a host however, it can live for 1-3 years if conditions permit. The fleas we see here on our cats and dogs are host specific, they can bite people, but since we are not their natural host they cannot reproduce or survive on a human blood-meal. Understanding the complexities of their lifecycle and knowing how they spread, helps us understand the best way to control and eliminate these pests.
Many pet owners know that they should protect their pets from fleas during the warmer months. What many people don’t realize is how important it is to ensure protection right up until we have a few days of heavy frost or snow on the ground. The weeks before that point are the most dangerous weeks for picking up fleas for the unprotected host. Also, given the fact that the pupa can survive camouflaged in your carpet and furniture for extended periods waiting to hatch, if your pet does pick up fleas at the end of the fall season, you will have to continue your treatment through most of the winter to get the problem under control.
Fleas are more than just an annoyance to our pets. Many dogs and even more cats are very allergic to fleas and the intense itchiness they suffer can lead to such a degree of scratching, biting and chewing that these poor pets can end up with a severe dermatitis, often requiring steroids and/or antibiotics for extended periods to get under control.
We strongly encourage flea prevention in all pets. It is much easier, less expensive and certainly kinder to our pets to keep the fleas from biting in the first place, than it is to try to deal with a flea problem once it’s in your home. Just remember that although we are fortunate here to have a brief reprieve over the winter, don’t make the mistake of stopping your prevention too soon.