May 07 2014


Nicole Jewett

After what seemed like a never ending winter, we are finally welcoming spring and…the dreaded fleas! As flea season is upon us, I decided to talk about fleas, their life cycle, common misconceptions and prevention.

The Flea

The most common flea found on our pets, both dogs and cats, is the cat flea (Ctenocephalides felis) which accounts for >90% of infestations.  Other flea types include the dog flea, the poultry flea and the human flea which are very uncommon.

The Life Cycle

–        The egg: About 1/3 of the flea population in the home is at the egg stage. The eggs are laid on the pet by the adult female flea. The eggs typically fall off the pet to hatch in the environment, typically in 2-12 days. These eggs are very small and seldom seen as they measure only 1-2 mm. Adult female fleas can lay up to 40 eggs per day! Once the eggs are in the environment, they will mature into larvae, providing the proper humidity (high) and temperature (18-26 °C) is present.

–        The Larvae: About 1/2 of the flea population in the home is at the larval stage. The larvae are similar to very small caterpillars that crawl around in the environment feeding on flea dirt. It is during this stage that the larvae will pick up tapeworm eggs and become carriers. During this stage, the larvae will mature overtime and become pupae. The larval stage can last 9-200 days depending on the environmental conditions.

–        The pupae: Not all larvae will mature to pupae as many of the larvae are killed before reaching this stage. Only about 8% of the larvae in the environment will reach the pupal stage. The larvae will spin a cocoon in which the pupae will develop. Once in a cocoon, they are very resistant to environmental stressors such as freezing, low humidity, insecticides, etc. and can remain at this stage for up to 1 year until the conditions are perfect! Vibrations, heat, CO2, sound and light will stimulate the pupae to emerge. Newly emerged fleas can survive 1-2 weeks before needing their first meal.

–        Adult: Once on a pet/host, the feeding flea will rarely leave. Fleas can spend their entire adult life on a pet and can survive for up to 100 days.  On average most adult fleas only live 4-6 weeks on a pet. The feeding female flea will begin laying eggs within 24-48 hours of a blood meal. If the feeding adult flea is accidentally knocked off the pet via scratching, brushing, etc. it will typically die within 2-4 days, unless it finds another host.

It is possible for then entire life cycle, from egg to adult, to be complete in as little as 3 weeks!


Common Myths

–        My pet cannot get fleas because it is completely indoors.

  • An indoor environment, such as most of our homes, is the perfect environment for fleas to thrive due to the constant temperature and humidity level. If you have pets, all you need is 1 flea to start an infestation.

–        My pet cannot have fleas because I (owner or family member) am not getting any flea bites.

  • Fleas do not prefer human blood and will typically not feed on humans unless absolutely necessary or flea numbers are very high.

–        We don’t have fleas because we do not have carpet in the house, just hardwood floors.

  • Fleas can develop in cracks in between the floor boards.

–        My pet cannot possibly have fleas as I am not seeing any.

  • If the flea burden if relatively small, you may not see them as they are very small and most pets are very good as licking them away.

–        My pet cannot get fleas because of his/her breed (i.e. Huskies because of their thick undercoat).

  • All dog and cat breeds are equally susceptible to fleas.

–        My indoor cat cannot get fleas because my dog is on flea medication.

  • Should the dog get fleas and they get knocked off before getting a blood meal (and getting killed or sterilized by the flea product) they could get on the cat and begin an infestation.


Consequences of Flea Infestation

–        Discomfort for the pet

–        Flea Allergy Dermatitis (hypersensitivity to flea saliva causing intense itching, hives, rash, skin infection, etc.)

–        Anemia, especially in the very young (puppies and kittens) and debilitated pets (elderly, pet with chronic disease, etc.)

–        Tapeworm Infection

–        Cat Scratch Fever (does not make the cat sick but the infected cat can make a person sick)


The best thing we can do as pet owners to prevent flea infestation is to protect all our pets during the flea season. Here in NB, the typical flea season is from May until November. However, any change in our climate (ideal flea humidity and temperature) could shorten or extend our current flea season. This could vary from year to year.  Some veterinarians may recommend having your pets on a flea preventative all year round.  Many products are available to prevent or kill fleas. The most common products are topical (applied on the skin) and oral medications.  These are given on a monthly basis during the flea season.

Flea products are available from your veterinarian but certain products can be found in pet stores or online. Some of the products in stores or online can be very different from the products you can get from your veterinarian with regards to safety and efficacy.  For further information, have a discussion with your veterinarian about which options are best for your pet.


Fleas: Know your Enemy. Veterinary Partner. Veterinary Information Network, Inc. www.veterinary

Fleas. 2010. Associate Database. Veterinary Information Network, Inc.

valleywebadmin |

Location Hours
Monday7:30am – 8:00pm
Tuesday7:30am – 8:00pm
Wednesday7:30am – 8:00pm
Thursday7:30am – 8:00pm
Friday7:30am – 5:30pm

Please note our phones are answered from 8am-7:30 Monday, Tuesday. Wednesday, and Thursday, and from 8am - 4:30 on Fridays.