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Flea Control
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Fleas are the most common
external
parasite of companion animals. Flea allergy dermatitis is the
most
common skin disease of dogs and cats! Flea control has always
been
a challenge for veterinarians and pet owners because the adult fleas
cause
the clinical signs, yet the majority of the flea population (eggs,
larvae
and pupae) are to be found off the pet in and around the home.
The
ideal flea control programe utilizes products that target the various
stages
of the flea life cycle, not only the adult fleas on the pet.
Generally the most effective are the treatments that are available as
prescription-only medications, so your vet is a good starting place to
ask for advice about which is most suitable for your dog.
For the flea allergic patient, continuous excellent flea control is
required to remain symptom free. Even very minimal exposure may
be sufficient
to perpetuate itching in a hypersensitive patient. In the past,
veterinarians
and pet owners always had to try to control fleas by treating the
environment
of the animal for the immature stages of the flea. This approach,
although
effective when properly instituted, is labour intensive and requires
frequent
repetitive applications. Also, some of the older products made
for
killing fleas on our pets do not kill fleas instantly or are not long
lasting
enough to really help flea allergy patients, because the female fleas
survived
long enough to lay a few eggs and perpetuate the life cycle.
The Life Cycle of the Flea: Ctenocephalides felis
The flea has the potential to breed inside your house within 12
days
and each female flea can lay several hundred eggs per week starting
24-48
hours after her first blood feed from your dog. Eggs are laid in
the
hair coat and are designed to fall off the host. They are resistant to
insecticides,
but susceptible to various insect growth regulators. Hatching and
survival
is dependent on temperature and humidity. Modern houses with carpets
and
central heating, providing an ideal microclimate for the larvae to
thrive
and feed on organic matter such as dead skin cells. Larvae
develop
in the host’s environment and feed on adult flea feces (blood) that
fall
out of the hair coat of the pet. Larvae are susceptible to
traditional
insecticides, borates and insect growth regulators. Larvae
eventually
spin cocoons (often within carpet fibers) for pupation. Pupae are
resistant
to freezing, desiccation, and insecticides. Pupae can lie dormant
for
many months; they are stimulated to expupate as emergent adults by
vibration,
warming and increased carbon dioxide. Normally, expupation occurs
when
a host is near and the new flea finds the pet within seconds of
emergence.
Emergent fleas are fairly mobile and can survive a few days without a
host,
if in a suitable environment. New fleas begin feeding within
hours
of finding a dog or cat. Once a blood meal has been taken, the
flea
can survive only a short time if it is dislodged from the host.
New
fleas experience very high mortality on healthy adult hosts. Most
fleas
do not survive 72 hours on an animal that is itching and able to groom
itself.
The adult flea usually lives for less than 20 days but due to the short
life cycle and high egg count, many thousands of fleas can form in a
room within a matter of a few weeks of a single female flea being
introduced into a household.
Unfortunately, limited egg production does occur even on allergic
animals.
The entire life cycle of C. felis can be completed in as few as 16 days!
Program® and Sentinel® (Lufenuron) from Novartis
A flea contraceptive such as Program which works by preventing the flea
pupa
from emerging from the egg. It is extremely effective and has a
high
safety margins. Where there are no fleas in the house, this
product
alone should prevent any household infestation so long as all dogs (and
cats)
in the house are treated at the same time every month. The
manufacturers
even guarantee its efficacy. Please remember it prevents flea
breeding
but does not kill fleas. These prescription drugs are available as a
once
a month flavored chewable (soy and pork) pill or oral liquid suspension
to
be given with a full meal. Female fleas that feed on pets treated
with
lufenuron produce sterile eggs. The product does not kill adult fleas.
It
is a very easy way to break the life cycle but pets remain fully
susceptible
to the emergence of any fleas from pupa already present in the
environment.
Therefore, 4 to 7 months may pass before the flea free state is
reached.
In order to stop the life cycle, every animal in the patient’s
environment
must receive lufenuron or another insect growth regulator. Pets
should
be treated for fleas with an adult flea-killing product during the
first
few weeks of starting Program®.
Frontline® Spray, Frontline Plus® and Frontline Top
Spot®
(fipronil) from Merial
Fipronil is a broad spectrum topical insecticide available as a spray
or
a drip-on. Fipronil binds chemically to the hair and is absorbed
through
the hair follicle by the sebaceous glands. Frontline Spray works
by
dissolving into the sebum (the fat covering of the skin) and hence
doesn't
get washed out by rain or even weekly shampooing. (It is not
recommended
to bath dogs 2 days either side of treating with Frontline as it may
reduce
its adherence and effectiveness.) It will last for up to 3
months.
In spray formulation fipronil may kill fleas at 95% for up to 30 days
after
application on dogs and stands up to biweekly bathing. It is
labeled
for puppies and kittens of 8 weeks (10 weeks for Top Spot®).
It
is also affective against ticks. The major problem with the spray is
the
high volume of alcohol based product that must be applied. Many
cats will show minor adverse reactions with this application technique.
The
product is labeled to be applied no more than once a month. Frontline
Plus®
contains the insect growth regulator, S-methoprene and so provides
control
of eggs and adult fleas.
Many of these are produced as an aerosol (eg. Frontline) and will kill
adult
fleas on the dog. Other products are produced as a monthly 'spot-on'
treatment
applied to the back of the neck and are very easy to apply, (eg
Frontline
Spot On and Advantage Spot On).
Advantage® (imidacloprid), K9 Advantix® (with permethrin),
Advantage
Multi® (with moxidectin) from Bayer
These products are available as a spot ons for either dogs or cats.
Advantage Multi® is a prescription drug that also is a heartworm
preventive. Advantage® seems to be very well tolerated by sensitive
cats. It provides flea knockdown in about 8 hours. 100% killing can be
maintained for at least two weeks. It
is susceptible to wash off, therefore outdoor active dogs and dogs that
swim
or that must be bathed because of dermatitis must be re treated
frequently. (Weekly re treatment is allowed with Advantage only®).
Imidacloprid has
no efficacy against ticks, but K-9Advantix®, with permethrin does.
K9
Advantix is only labeled for once a month, and ONLY FOR DOGS.
An environmental
insecticide
Indorex products by Virbac are used to spray your house.
All
the rooms where your dog (and cat) may have access must be
treated.
It has two functions: Firstly, a chemical which kills any adult fleas
in
the room and secondly an 'insect growth and development inhibitor'
which
prevents the eggs and larvae progressing to their next stage and lasts
for
up to 7 months. Acclaim adheres at the base of the carpet where
the
flea larvae live (other household sprays do not adhere and are vacuumed
up).
Spray your rooms with this product twice a year and you will
substantially
depopulate the house of fleas. (Read the directions carefully as many
are
potentially toxic to fish)
About Traditional Insecticides / Over-the-Counter Flea Control
Products
Several adulticide insecticides or shampoos are available and some have
insect growth regulators such as s-methoprene included. Shampoos
are
less effective than sprays, dips or spot ons because they have little
residual
activity. For cats, pyrethrins as sprays or foaming mousses may
useful
for safe, quick knock-down of fleas. For dogs, permethrin sprays or
spot-on
products with methoprene or Nylar may be effective, but cats MUST NOT
BE
EXPOSED directly or indirectly to permethrin products. There is some
resistance
in fleas to permethrin products now documented. Over-the-counter
products
with etofenprox and S-methoprene can be used with some caution in cats
and
may be effective in some settings but are not fast enough for good
results
in flea allergy.
Treat all animals in the household at the same time, not just those
showing immediate signs of flea infestation.
Natural Solutions
Flea Combs
These catch adult fleas found in the coat, which can move quickly and
be hard to catch. Have a bowl of soapy water to hand to drown
them in.
Electronic Flea Combs and Brushes
These zap any adult fleas found in the coat.
Food Supplements
It is thought that sime supplements such as garlic and brewers yeast
can help deter fleas by making the host animal less 'tasty'.
Flea Traps
These will catch only adult fleas, and need to be sited near to places
frequented by your dog, so you may need several.
Pest Repellers
Electromagnetic and/or ultrasonic technology are supposed to create an
unpleasant environment for fleas, but they tend to have limited cover.
When it comes to using herbal products or those containing essential
oils, its important to remember that just because they are 'natural'
doesn't necessarily mean they are safe.
Pennyroyal, for example is recommended but can cause skin irritation,
liver and neurological damage and can be toxic if ingested.
Herbal and essential oil remedies are specialist areas and it is best
to consult someone qualified and knowledgeable about there use for
animals rather than trying to make up your own anti-flea preparations.
Vacuuming
Regular thorough vacuuming has been shown to remove up to 20% larvae
and 32-59% of
flea eggs from a carpet. A good tip is to spray the inside of your
vacuum
cleaner bag with Acclaim or place a flea collar in the vacuum bag eg.
Vetkem
Dog Flea Collar. Wash all your pet bedding in hot soapy water,
including fleeces and throws used to protect furniture or car interiors.
Do bear in mind that a very high percentage of dog skin conditions are
caused
by fleas and that the above control measures will work if thoroughly
carried
out. Also remember that 80% of fleas infesting dogs can be cat fleas,
so
flea control in your cat (if you have one) is also very important.
The above information is simply informational. It's intent is
not
to replace the advice of a veterinarian nor to assist you in making a
diagnosis
of your pet. Please consult with your own veterinarian for confirmation
of
any diagnosis. Your pets life may depend on it.