Many owners are lulled into a false sense of security because they don’t see visible signs of fleas on their pets. They may think that they can afford to forego preventive treatment. However, fleas are good at hiding in your pet’s haircoat and in the environment. Their bodies, sleek and thin, are extremely well adapted for scurrying and disappearing in dense fur, especially near the ears, tail, head, and groin. Unless you are expressly looking for them, you may never actually see them. When infestations are mild or emerging, many owners may think that their pet’s itching or scratching is part of its normal grooming behavior. Cats, in particular, being the fastidious groomers that they are, are very good at grooming fleas off of themselves.  That, however, doesn’t stop new fleas from jumping on them.

Fleas are well adapted to survive a broad range of environmental conditions and are very capable of surviving indoors year-round, even during winter. Keep in mind that the adult fleas you may or may not see on your pet represent only 5% of the flea population. The other 95% are lurking in various immature stages in your pet’s immediate environment — in bedding or carpeting or hiding in hard-to-reach crevices. While flea pupae normally hatch in about two weeks, they can exist in a suspended state for weeks or even months when environmental conditions aren’t just right. This dormancy period means that you may have a continually emerging source of new adult fleas for up to several months, even after you have started treatment. Most topical or oral flea-prevention medications require the adult flea to actually be on the pet or to ingest a blood meal in order for the flea to be killed. And, the environmental sprays that must be used in extreme infestations aren’t always effective against all of the life stages of immature fleas, particularly if pupae have hidden themselves in hard-to-reach places.

In addition, fleas are ubiquitous in the environment, and it is easy for pets to pick them up while outside. Fleas can be carried into your yard and even into your home by local wildlife, such as raccoons and mice. 

Be Pound Wise, Not Penny Foolish

These special life-cycle and environmental adaptations can lead many owners to think that flea-prevention products don’t work and aren’t worth the investment, because they may continue to notice new fleas. The reality, however, is that they do work and are highly effective over time when used as directed. The best way to avoid fleas is to use one of the many proven topical or oral monthly flea-prevention products that are available on the market. These products are very safe and easy to use.  Be sure to ask your veterinarian for recommendations on how to prevent and control these pests.


This article originally by Beth Thompson, VMD appeared in PetsMatter Sept/Oct 09 - Volume 4 Issue 5, published by the American Animal Hospital Association. Copyright © 2009 AAHA.

Reprinted with permission from the American Animal Hospital Association.