Fleas have traditionally been one of the most common, and most stubborn, parasites to control on pets. To gain control, it is necessary to understand the insect's life cycle, and make sure that ALL stages are addressed at the same time.
Fleas have a typical four stage insect life cycle. Flea eggs usually fall off of the host animal and land in the bedding material where the pet rests (a typical adult female cat flea will lay approximately 50 eggs per day - in Indiana, practically ALL fleas seen are cat fleas). Under favorable conditions (temperature above 65° and humidity above 70%) the eggs will hatch in a few days. Hatching may be delayed up to a few weeks. The larval fleas (small ugly caterpillars) feed on detritus (dry skin flakes, stool of adult fleas, etc.) in the environment. Again, in a few days or up to a few weeks, the larva will spin a sticky cocoon to anchor it to the carpet fibers, baseboards, etc, and lie dormant until ready to emerge as an adult. Under ideal conditions, this may be as short as seven days, or take up to 140 days before emerging to look for a new host. Flea cocoons are resistant to all currently available insecticides.
For every adult flea on the pet, there are usually at least 10 viable eggs, 7 larva, and 2 pupa waiting to take its place. In order to eliminate the flea population, each of these life stages must be taken into count, or we will not get rid of the pests.
One approach to accomplishing total flea control, when an infestation is already present consists of:
- Spraying or fogging the entire house with a product that includes both an "adulticide" and an Insect Growth Regulator (IGR).
- Spot treating under furniture and pet bedding.
- Yard and kennel spray for outdoor areas frequented by the pet.
- Using a residual insecticidal treatment on all mammal , (guinea pigs, rabbits, rodents, cats, etc), pets in the household (Frontline®, Revolution®, Advanticks® or Advantage® treatments, or a pyrethrin powder for smaller sensitive animals). For Dogs only, Comfortis® or Trifexis® tablets are great alternatives.
Before applying a premise spray or fogging the house, vacuum thoroughly then throw the vacuum bag away. Vacuuming will trigger many of the pupa to hatch out into the more susceptible adult stage. It may also pick up some of the eggs, larva, or cocoon stages and mechanically remove them (but not kill them). Do Not re-vacuum for a few days after spraying.
Most insecticides used in flea foggers and premise sprays only kill adult fleas ("adulticides" these include: Carbamates (Carbaryl/ Seven®/Methomyl), pyrethrum & permethrin compounds, organophospates (Malathion/Diazinon/Dichlorvos/Thion/Fenthion/Trichorfon) are the most common types. Pyrethrin and permethrin formulations are the safest of the effective types but (especially long lasting formulations) may be toxic to some sensitive dogs (the sight hound group) and many cats. Try to select a product for the first treatment that includes both an adultacide and an insect growth regulator (IGR) such as Methoprene (also called Precor®), Fenoxycarb®, or Nylar®, to kill the egg and larval stages. Insect Growth Regulators are extremely safe and virtually non-toxic. Frequently IGR's stay in the environment for weeks (Methoprene) or months (Fenoxycarb®/Nylar®) to keep killing new flea eggs, thereby preventing fleas from reestablishing themselves in the household. It is important to remember though that these IGR's have no effect on the adult fleas themselves. It is also important to remember that cocoons may still be present, so adults will reappear in a few days to weeks. This is why we recommend retreating the home with an adultacide type spray a second time two weeks after the initial treatment. Surprisingly, most serious reactions to household insect sprays are not to the insecticide, but one of the "carrier" chemicals which keep the insecticide in solution or push it out of the can, these carriers may cause reactions for 24 to 48 hours in susceptible people or pets.
During pregnancy or when small children are present in the house, it is best to hire a professional exterminator to do the house treatment and allow our staff to treat the pets in our clinic. To reduce the danger of poisoning your pet, consult with the veterinarian about which individual chemicals or sprays might be safest for your pets health conditions, and if you have a professional exterminator, have them give you a list of the chemicals that they are or will be using.
►If fleas have not yet found your pet(s), we have several much simpler options to keep fleas a bay. First, you can treat the environment with one of the long lasting insect growth regulator sprays on the market now (some sprays include only Fenoxycarb® or Nylar®, with no adulticide). This will prevent fleas from being able to reproduce in your house for two to four months. Secondly, you can place all pets in the house on a flea preventive product: lufenuron (Program® six month injectable, or monthly Program® suspension or tablets for cats, monthly Program® or Sentinel® tablets for dogs), or a flea treatment (Frontline Plus, Trifexis, or Revolution). Lufenuron acts on any flea that feeds on your pet(s) and works like an insect birth control pill, preventing any new fleas from being made. If you live in area with a major outdoor flea problem, or your pets frequent public parks, something to kill adult fleas on your pet will be a better choice. We recommend Lilly's new Comfortis® or Trifexis® flea tablets, however, if you also fight ticks, Frontline Plus® is a great choice. Both of these products last one month, and being a tablet, Comfortis® is safe around children. Frontline® comes as a spray (Frontline® Spray) or spot-on treatments(Frontline® Plus). Frontline® Plus and Comfortis® are packaged for dogs by the pets weight. For cats, we recommend Revolution® which offers the same protection against fleas as Frontline®, but also has the benefit of covering roundworms, hookworms, heartworms and ear mites. A recent study showed that 11 % of cats in IL and IN (more than 1 in 10) had been exposed to or infected with heartworms.
It is worth mentioning that lawn treatments used for grubs, whether "chemical" or the more natural "organic" products, also are a benefit in reducing flea exposure when pets go outdoors and may reduce fleas from entering through screen doors. For flea control, yard treatments do not need to cover the entire yard as most fleas will be found in the shady areas under decks, around bushes and in flower beds, where the pets also like to rest. It turns out that direct sunlight is very effective at killing flea larva. Before you rush out and soak your lawn in insecticide, there are studies showing links between insecticides, herbicides, and lawn fertilizers with some cancers in pets and people, or it might be worth considering trying Milky Spore, or one of the other insect parasite lawn treatments.
To date, no controlled studies of yeast, garlic, ultrasonic flea collars, or other "organic" or "natural" flea control methods have shown any effect on fleas. The closest are the various parasitic nematodes which feed on insect larva in the soil. Garlic has been associated with a few poisonings of pets when they were given too much, as have "unrefined citrus extracts" in some "healthy" over the counter sprays. Some pets have shown behavior changes with prolonged exposure to ultrasonic noise, so even that treatment is not completely safe.