Fleas are tiny, strong and can be very fast (especially when jumping or moving around in your pet’s coat).  They can jump 10,000 times in a row (the length of three football fields). Three pairs of legs make for excellent leaping capabilities (up to two feet) and they do not have wings.

Fleas are most commonly found at the base of the tail.  You will normally see what we call “flea dirt”, which is the digested blood.  It looks like ground pepper in your pet’s fur.  You can also see the adults moving around, but they are very, very swift moving!

With heavy infestations, however, fleas can thrive anywhere on the body.  Fleas prefer to wait and jump onto a passing animal. Once aboard, they remain until they are dislodged or groomed from the animal.  On short-haired cats and dogs fleas survive an average of 8 days; they live longer on long-haired animals.  A female flea can start to reproduce within a day or two, she can produce thousands of eggs during a feeding.  They feed once to twice daily, and will then remain on the pet until they are done or dislogded.

Adults are parasites that draw blood from a host.   Larvae feed on organic debris, particularly the feces of adult fleas, which contain undigested blood. Fleas commonly prefer to feed on hairy animals such as dogs, cats, rabbits, squirrels, rats, mice and other domesticated or wild animals.

Flea Life Cycle

The life cycle of the flea is composed of the egg, larval, pupal and adult stages. Cycle length ranges from several weeks to several months and is largely dependent upon environmental conditions.  With a complete life cycle ranging anywhere from 16 days to 21 months, depending on environmental conditions.


Fleas lay about 40-50 eggs a day, thousands in her lifetime.  Unlike the eggs of some other parasites, flea eggs are not sticky and usually fall to the ground immediately upon being laid. Flea eggs hatch into larvae within 1 to 12 days.  Flea eggs represent about one-half of the entire flea population present in an average home.

Eggs are no larger than a grain of sand, meaning they are essentially microscopic!!!!


The larval stage lasts from 4 to 18 days.  Once away from the host, the larvae seek out shaded locations such as cracks in the floor, in carpets, base boards, pet bedding or protected locations under and in furniture. Flea larval survival depends on relative humidity and temperatures. Since dehydration is fatal to flea larvae, they will not survive relative humidity less than 45-50 percent or soil temperatures greater than 95 degrees Fahrenheit. However, outdoor larvae will survive in cool, shaded areas and do very well in crawl spaces. In environments of suitable humidity and temperatures, fleas will develop year round. Larvae spin silken cocoons and enter the pupal stage.  The pupal stage may be complete within three days.  Fleas in the pupal stage will become adults more rapidly in the presence of warmth and high humidity.

Controlling flea larvae usually involves using vacuums to remove.  Larvae make up about 35 percent of the flea population, while the pupal stage accounts for 10 percent.  They are also microscopic!


Adult fleas begin searching for food when they emerge from the pupal stage. Fleas are noted for their jumping abilities, they will remain stationery when a suitable host is located. Females begin laying eggs within 48 hours of the first feed, thus beginning the life cycle again.  They only make up about 5 percent of the population

Fleas In The House

Fleas depend on a blood meal from a host to survive.  They can come in on your pet (even if they just go outside to do their business and come right back in).  They can even come in on you, they take a ride on your shoe or pant leg without you even suspecting they are there.  They are also small enough to fit through screens on doors or windows.

Fleas only need 30-40 degrees to come out of hibernation!

Although fleas do prefer warm weather, your cozy house provides the perfect environment for the parasites to thrive in during the colder months. Sure, freezing temperatures might kill some of them off but not the ones that are sheltered.  They like to hide in nests, burrows, garages, under porches, in your car or in your living room.  Plus, if there are no hosts to feed on, developing fleas can become dormant. This means they’ll just wait around to emerge until conditions are right again.

Fleas are a year-round problem, which is why year-round control is so important.

Did you know that adult fleas only account for 5% of the total flea population!!!!

The other 95% are the eggs, larvae and pupae- they are microscopic and we cannot see them!  They are hidden in our carpets, furniture, bedding (pets and ours), gardens, garages, under porches waiting for a pet to walk by so when they are adults they can jump on and start the life cycle again!

Signs of Fleas

Many signs can indicate flea activity.  A common indication would be pets that repeatedly scratch and groom themselves. Flea dirt, the adult flea feces, also can indicate activity. Flea dirt looks similar to coarse ground black pepper and may be seen on the pet, in pet beds, carpets, rugs and other areas where the pet rests.  Typically you will find the flea dirt at the base of the tail, along with scabs if the pet is allergic to the bites.  This area is called the caudal dorsum.  If your pet is itchy at the base of it’s tail or down its legs, or has scabs there… reasons for this problem are Fleas!… #1, 2, and 3.

Other common indications of fleas include:

– Allergic dermatitis

– Excessive scratching, licking or biting at skin (especially the backs of legs, backend, around the base of the tail)

– Hair loss

– Scabs and hot spots

– Pale gums

– Tapeworms

Since fleas can consume 15 times their own body weight in blood, they can cause anemia or a significant amount of blood loss over time. This is especially problematic in young puppies or kittens, where they have an inadequate number of red blood cells.  Signs of parasitic anemia include pale gums, cold body temperature and listlessness.

When a dog or cat has a heightened sensitivity to the saliva of fleas, just ONE BITE of a flea can cause an allergic reaction. This condition is known as flea allergy dermatitis and causes intense itching and discomfort for your dog or cat. Signs include generalized hair loss, reddened skin, scabs and hot spots (dogs) or potentially eosinophilic granulomas (cats). Flea allergy dermatitis often leads to skin infections.

In order to treat for fleas, you need to have ALL pets in the house on preventative for a minimum of 3 months.  That will break the lifecycle of the flea.  When a flea bites and starts to lay eggs, those eggs do not hatch out typically 1-2 months later.

Treatment for your house is vacuuming (cushions, rugs, baseboards, any darkened areas, etc).  And continuously washing bedding or wherever your pets like to lay.  If needed we do have products that we have had success with at the clinic, called Knock-Out spray.  It is a premise spray, but you must use it with no pets in the area.  Please consult one the of the veterinarians before use.

DO NOT Use to Treat Fleas:

– Flea shampoos: they can be very stripping to your pets skin and can remove topical flea medications.  They can remove the adult fleas, but they will generally only last a few days and the fleas will be right back on your pet.

– Flea collars: they are only effective in the area where the collar lays.

– Over the counter flea medications (medications found in stores, online, etc): these flea medications are not the same as veterinary approved medications (even the flea medications that have the same name).  They generally last HALF the amount of time, 2 weeks on average and can potentially cause side effects.  These products are also known for not being labeled as what they truly are (false products), the amount of the medication may also be incorrect.  For these reasons, manufacturers do NOT back these over the counter products!

Flea Preventatives:

Nexgard: Treats for fleas and ticks; oral once monthly (dogs)

Bravecto: Treats for fleas and ticks; oral every 3 months (dogs)

Advantage: Treats and prevents fleas; topical once monthly (dogs and cats)

Advantix: Treats and prevent fleas and ticks; topical once monthly      DOGS ONLY

Frontline Gold: Treats and prevents fleas and ticks (it also helps to kill the next generation of flea eggs and larvae before they can develop into adult fleas); topical once monthly (dogs and cats)

Revolution: Treats for fleas, American Dog tick, and heartworm; topical once monthly (dogs and cats)

Trifexis: Treats for heartworm and flea preventative; oral once monthly      DOGS ONLY

For more information about fleas please visit: http://www.capcvet.org

For more information about fleas please visit: http://www.petsandparasites.org