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Successful flea control has two
aspects. Fleas must be controlled on your pets, and fleas must
be controlled in your pets’ environment. Since cats and dogs
share the same fleas, the presence of both species in your pets’
environment can make flea control much more difficult. All pets
in a household must be effectively treated, even if it appears
that only one pet is being bothered by fleas.
Diagnosis
of Flea Infestation
When a dog or
cat is heavily infested with fleas, it is easy to find the
fleas. If the numbers are small, it is best to quickly turn
your pet over and look on its belly. If you do not find fleas
there, look on the back just in front of the tail. Be sure to
part the hair and look at the level of the skin. Also look for
"flea dirt." Flea dirt is digested blood left behind by the
fleas. Flea dirt is actually fecal matter from the flea.
Finding flea dirt is a sure indication that fleas are present or
have been present recently.
Flea dirt
looks like pepper. It varies from tiny black dots to tubular
structures about 1/32" (1-2 mm) long. If you are not sure it is
flea dirt, put the suspected material on a light colored
tabletop or counter top. Add one or two drops of water and wait
about 30 seconds. If it is flea dirt, the water will turn
reddish brown as the blood residue goes into the solution.
Another trick is to put some of the material on a white paper
towel and then wet the paper towel with water. A red stain will
become apparent if you gently wipe the material across the
surface of the paper towel.
Many people
find tiny drops of blood in a pet's bedding or where the pet
sleeps. This is usually flea dirt that was moistened, then
dried. It leaves a reddish stain on the bedding material and is
another sign that fleas are present.
Life Cycle
of the Flea
To appreciate
the complex issue of flea control, you must understand something
about the flea's life cycle.
Although you
are only able to see the adult flea, there are actually 4 stages
of the life cycle. The adult flea constitutes only about 5% of
the entire flea population if you take into account all four
stages of the life cycle. Flea eggs are pearly white and about
1/32" (1-2 mm) in length. They are almost too small to see
without magnification. Fleas lay their eggs on the pet, but the
eggs do not stick to your dog or cat's hair. Instead, they fall
off into the pet's environment. The eggs make up 50% of the
flea population. They hatch into larvae in 1 to 10 days,
depending on the temperature and humidity in the environment.
High humidity and high temperature favor rapid hatching.
Flea larvae
are slender and about 1/8-1/4" (2 - 5 mm) in length. They feed
on organic debris found in their environment and on adult flea
feces, which is essential for successful development. They
avoid direct sunlight and actively move deep into carpet fibers
or under organic debris (grass, branches, leaves, or soil).
They live for 5 to 11 days before becoming pupae.
Moisture is
essential for their survival; flea larvae are killed by drying.
Therefore, it is unlikely for them to survive outdoors in areas
of strong, direct sunlight. Outdoor larval development occurs
only where the ground is shaded and moist and where
flea-infested pets spend a significant amount of time. This
allows flea feces to be deposited in the environment. In an
indoor environment, larvae survive best in the protected
environment of carpet, along baseboards, under and inside
upholstered furniture, or in cracks between hardwood floors.
They also thrive in humid climates.
Following
complete development, the mature larvae produce a silk-like
cocoon in which the next step of development, the pupa,
resides. The cocoon is sticky, so it quickly becomes coated
with debris from the environment. This serves to camouflage
it. In warm, humid conditions, pupae become adult fleas in 5-10
days. However, the adults do not emerge from the cocoon unless
stimulated by vibrations, carbon dioxide, and heat.
Pre-emerged
adult fleas can survive up to 140 days within the cocoon.
During this time, they are resistant to insecticides applied to
their environment. Because of this, adult fleas may continue to
emerge into the environment for several weeks following
insecticide application.
When the adult
flea emerges from its cocoon, it immediately seeks a host
because it must have a blood meal within a few hours to
survive. It is attracted to people and pets by body heat,
movement, and exhaled carbon dioxide. Following the first blood
meal, female fleas begin egg production within 36 to 48 hours.
One female flea typically produces 40 to 50 eggs per day. Egg
production can continue for as long as 100 days, which means
that a single flea can produce thousands of eggs in her short
lifetime!
This entire
life cycle (adult flea >>> egg >>> larvae >>> pupa >>> adult)
can be completed in 14-21 days with the proper temperature and
humidity conditions, but it may also take much longer if
environmental conditions are not ideal. This adds to the
problem of flea control.
If untreated,
the female flea will continue to take blood for several weeks.
During that time, she will consume about 15 times her body
weight in blood. Although the male fleas do not take as much
blood, they, too, contribute to significant blood loss. This
can cause a pet to have an insufficient number of red blood
cells, which is known as anemia. In young or debilitated dogs
and cats, this anemia may become severe enough to cause death.
Flea
Control
Successful
flea control must rid your pets of fleas and it must rid your
pets’ environment of fleas. In fact, environmental control is
as important as treatment of your pet. If your dog or cat
remains primarily indoors and you do not have other pets that
come in from the outside, environmental control is relatively
easy, especially with the advent of the newer topical and oral
products (see below). However, the dog or cat that goes
outdoors frequently, or stays outdoors, presents a greater
challenge and a few fleas may occasionally be seen indoors.
Many of the
older insecticides (which have been the mainstay of flea control
for years) have limited effectiveness against fleas because they
are only effective for a few hours after application on the
pet. Also, these are primarily geared to kill adult fleas.
Flea powders, sprays, and shampoos will kill the fleas present
on your pet at the time of application. However, most of these
products have little or no residual effect, so fleas that return
to your pet from his environment after the pet is treated are
not eliminated by these products. Thus, your dog or cat may be
covered with fleas within a day after having a flea bath or
being sprayed or powdered.
However, there
are some newer, more effective sprays that can be a valuable
part of the overall treatment plan. They kill adult fleas
rapidly and are safe enough to use daily, if necessary. Flea
sprays containing insect growth regulators are helpful in
managing the overall problem because they help to break the flea
life cycle by decreasing the number of flea eggs that hatch. In
general, flea sprays, collars, powders and dips have become less
popular since the introduction of the newer, safer and more
effective products.
Newer
Products
There are
several newer topical treatments that are applied to the back of
the pet’s neck. Frontline PlusTM
and AdvantageTM
are two very effective products; because they remain topical
and are not absorbed through the skin they are also extremely
safe. Both kill adult fleas for a full month. Frontline Plus
also kills ticks and contains a second ingredient that helps
kill flea eggs as the female flea deposits them on your pet’s
skin. There are many other products that are designed to be
used once a month and are applied in a similar manner to these
two. All have specific advantages and disadvantages. Ask your
veterinarian about any of these products prior to using them.
Be careful! Some of these other products cause severe illness
or fatalities if used on cats or debilitated dogs. Never use
any flea product that is labeled “for dogs only” on a cat; fatal
reactions can occur!
A new product,
known as ComfortisTM, is a meat-flavored “flea pill”
that is administered once a month. It is currently approved for
use in dogs only, but research is ongoing regarding a possible
future formulation for cats. ComfortisTM has one
big advantage over the topical monthly medications – it kills
the adult fleas on your pet much faster, thereby reducing the
number of flea eggs shed into your pet’s environment.
Another
meat-flavored, monthly “flea pill” is called ProgramTM.
This medication does not kill adult fleas but it does kill flea
eggs and larvae. When the female flea produces eggs, the eggs
do not hatch. In effect, this product acts like a birth control
product for the flea. Giving this product has the effect of
treating your house for fleas without spraying anything in your
house. This very safe product is available for both dogs and
cats. The monthly pill for dogs is available alone (ProgramTM
tablets) or combined with a heartworm preventative (SentinelTM
tablets). Cats may also take a monthly ProgramTM
tablet or monthly ProgramTM
liquid oral preparation. In addition, there is an injection
available for cats to be administered by your veterinarian which
will provide the ProgramTM
flea egg control for 6 months after a single injection. Because
of its effectiveness in controlling the flea egg population, the
consistent use of ProgramTM
(or SentinelTM) is an excellent way to help prevent a
flea infestation from occurring in your home in the first place.
If you have
any pet species other than dogs or cats in your household, check
with a veterinarian familiar with the species to determine which
product(s) will be most safe and effective for them.
Environmental Control
The newer
topical and oral products do not require the aggressive
environmental control that is necessary if only dips, sprays, or
collars are used. This is one reason why they have become so
popular with pet owners. Many people try the newest products
for 1-2 weeks to see if they provide adequate flea control
alone. Please consult with us about the requirements for your
specific situation.
When
environmental flea control is indicated, it must be directed at
both your house and your yard. Remember: adult fleas live on
animals; flea eggs, larvae and cocoons are everywhere else.
Therefore, when treating the environment, concentrate on
killing those eggs and larvae! Remember also, no chemical will
kill the cocooned stage of the flea. The only way to eliminate
the cocooned stage is to wait for the adult flea to emerge, and
then kill the resulting adult flea. Your veterinarian will be
able to help you choose the most effective products for your
situation.
House.
Even though large numbers of flea eggs, larvae and cocoons may
be in your house, most people never see them. A professional
exterminator may be called to treat your house or you may use a
house fogger or a long-lasting spray. You should purchase a
fogger or a spray that kills the adult fleas and inhibits
development of the eggs and larvae. In climates with extended
warm temperatures and high humidity, it may be necessary to
treat two or three times with a 30-day residual product before
all stages of the fleas are removed from the house. The second
treatment is most effective if it is done 2 weeks after the
first.
As a rule,
flea eggs and larvae tend to concentrate at the edges of rooms,
along the baseboards, under furniture, inside upholstered
furniture and deep inside carpets. Thus, sprays applied
directly to these areas are generally more effective than
foggers. Fogger mists tend to fall out of the air in the center
of the room, and access areas under and inside furniture very
poorly. Fogger sprays also do not turn corners well, so an
individual fogger is generally necessary for each room in the
house. Therefore most homes require less product to be used if
sprays are utilized instead of foggers.
Yard.
Yard control may also be done by professional exterminator or
with various products you may use yourself. Be sure that any
insecticide that you use has a 30-day residual. This keeps you
from having to spray every week. In climates with extended warm
temperatures and high humidity, it will often be necessary to
treat monthly during the warm months of the year. You should
use a 30-day residual product each time. Concentrate your
spraying to the cool, moist areas of your yard, especially the
areas where your pets like to stop and rest.
Re-emergence of Fleas
If you recall,
a pre-emerged adult flea can survive up to 140 days within the
cocoon. This is significant when your pets are gone from home
for extended periods of time. During the time that the house is
quiet and empty, the fleas present in your home continue their
development from egg to larvae to cocoon. But without their
mammalian hosts’ activity in the house, the pre-emerged adults
remain in their cocoons. Even if the house was treated with an
insecticide, their cocoon protects them. When people and pets
return to the house, the adult fleas emerge from their cocoons
en mass and immediately begin to seek a blood meal. They jump
on cats, dogs, and even people. Although it may appear that a
dog just returned from boarding brought fleas to your home, it
is also very possible that a sudden emergence of adult fleas may
account for the fleas present. If large numbers of fleas are
seen, they are almost certainly newly hatched fleas and have not
come home with your pet.
Additional information regarding pet
health may be found in our Medical
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