flea_control1Understanding the Flea Life Cycle

The most common flea found on cats and dogs is the cat flea (Ctenocephalides felis). Adult fleas consume a blood meal multiple times per hour.  The female can lay 27 eggs per day within 24-48 hours after her first blood meal.  These eggs fall off the pet and can hatch within 10 day or may stay in the environment for up to 133 days if there is no host present.  These eggs then hatch into larva, which eat organic debris for 5-12 days.  They then change into a pupae, the most resistant life stage.  They will emerge as an adult in as early as 8-9 days or may wait for many months until the conditions are right.   Newly hatched adult fleas jump onto a host animal to complete their life cycle.  Under ideal conditions, the flea can complete its entire life cycle in as little as two weeks; in adverse conditions, the cycle can take as much as a year.


How Fleas Affect Dogs and Cats

The most common symptom of a flea infestation we see in pets is itchy skin.  Some animals will scratch excessively leading to secondary skin infections.  Occasionally animals can become allergic to flea bites.  In these cases as little as one bite can result in excessive scratching, self trauma and secondary skin infections.  Young or even older debilitated animals can actually become quite ill and anemic (low red blood cell count) if they have a large enough flea burden.   The flea also acts as the intermediate host for tapeworms.  When pets swallow an infected flea while grooming, the tapeworm larva will develop into an adult tapeworm. Any animal with fleas is likely also to have a tapeworm infestation. It is recommended to treat your pet for tapeworms if they have been found to have fleas.

How to Treat a Flea Infestation

Although most over-the-counter topical insecticides will kill adult fleas, most have limited effectiveness because they only work for a few hours after application. This is particularly true of flea shampoos and powders; they kill fleas present on your pet at the time of application but have little residual effect; the following day the pet may again have fleas. Flea collars may seem very convenient but they don’t work well and are not recommended. Furthermore, flea collars, especially ones with a strong pesticide smell, may be harmful, or may cause a skin reaction or rash.  Some over-the-counter topical insecticides are even toxic and deadly for cats.  Using these products can not only be dangerous but usually end up being costly due to their ineffectiveness.

Luckily there are safe, fast and extremely effective flea treatments and medications available through your veterinarian.  All the fleas on your pet will die within 24 hours of the first treatment.  Each treatment works for a full 4 weeks to kill any live fleas that jump on your pet.  A flea infestation can be taken care of in as little as 3 monthly treatments. These products not only eliminate fleas from your pet, they also will work to kill fleas in the environment eliminating the need to spay pesticides on your home.  It is important that all the pets in the house are treated otherwise the fleas will continue to live on the untreated pet and the infestation cannot be eliminated.

How to Prevent a Flea Infestation

The best way to avoid a flea infestation in your home is to use a monthly flea preventative medication during the warmer months.  Prevention starts in June and extends to November.  November may seem late but we actually see most cases of flea infestation in the late summer and fall.  The chance of contracting fleas doesn’t decrease until we start to see frost. Any pet that goes outdoors, even if it is just to sit on the front porch, should be on a flea preventative.  Also, be aware that indoor cats can also become infested with fleas!  They can be contracted simply when you cat sits in a screened in windowsill.  You are also able to carry fleas and eggs in the house on your own clothing and shoes.  In some instances year round flea prevention may be necessary.  For example, some apartment dwelling pets can be at risk year round as fleas can travel from one apartment to the next.

If you have any further questions about flea treatment or prevention please do not hesitate to call us at (905) 385-5354.


This client information sheet is based on material written by: Ernest Ward, DVM

© Copyright 2009 Lifelearn Inc. Used and/or modified with permission under license (Modified by Mountain Animal Hospital October 9, 2013.




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