We are in the thick of flea season, so it might be appropriate to review proper flea control. Don’t underestimate the enemy—it has been around for millions of years and is not going away any time soon.
Fleas thrive in warm, moist environments. Their diet is made up mostly of blood from biting your pet. Flea saliva is irritating and causes an allergic reaction, leading to itching, scratching, and other symptoms of flea allergy dermatitis (FAD). We have a detailed page on skin allergies on our web site.
Fleas also spread tapeworms. If a flea infestation is severe enough or if your pet is very young, old or has a medical problem, it can cause anemia. This is especially important in older cats with chronic renal failure (kidney disease) since some of them are already anemic.
With the advent of a relatively new class of flea products called insect-growth regulators and insect-development inhibitors, we have at our disposal effective and convenient preparations to help win this battle. General acceptance of these new products has resulted in a major advance in flea control, and when the name-brand products are used as intended, you will have effective flea control.
Let’s look at the life cycle of a flea, divided into four primary life stages. When an adult flea sucks blood, it eventually deposits up to 50 white eggs per day on your pet. These rapidly fall into the environment. For most households, this means under the carpet, under furniture, or in shady areas outside, like porches and decks.
Depending on humidity and temperature, the eggs turn into larvae anywhere from a few days to a few weeks later. They look like small maggots at this stage and feed on the blood from the droppings of adult fleas, organic material like food crumbs, the shells from their eggs and other larvae. They remain larvae, feeding all the time, for up to three weeks. At this point, they spin a cocoon and become a pupa.
In this cocoon stage, they transform from larvae into adults. This can take one to two weeks, although it can take a much longer time if environmental conditions are not right. Warm temperatures, high humidity, vibrations of living things and carbon dioxide are all stimuli to speed the process. When they emerge from the cocoon, they are adult fleas ready to suck blood and lay lots of eggs again.
This life cycle has a variable timetable. What’s important to remember is that in the summer months, this complete cycle can be completed in two to three weeks. It is these new fleas, not the ones that are immediately killed when you administer flea products, that are the source of continual infestation, skin conditions, frustration and supposed failure of the product.
How do these relatively new flea preparations work in relation to this life cycle? When you apply a product that lasts one month, which most of them do, the adult fleas on your pet are killed from several hours to several days after application. The residual activity of these products keeps on killing the newly hatched fleas for one month, after which you again reapply your flea product.
Killing these newly hatched fleas over the month disrupts the life cycle and starts reducing the number of fleas turning into larvae and pupae. Thus, fewer and fewer fleas will be able to complete the life cycle as time goes on. You will continue to see fleas on your pet during this time, but they should disappear gradually.
Within three to eight weeks—sometimes longer, depending on their life cycle in your immediate environment—all the fleas will be eliminated from your immediate environment and your pet will no longer be affected as long as you remain there. This assumes you are treating your pet every month. If you miss a monthly treatment or do not apply the product properly, enough fleas survive to keep their life cycle going and your pet will continue to have them.
The bottom line here is to treat your pet every month (or more often, if your vet recommends it), and your flea problem should be controllable. In some cases, you may need direct environmental control, especially if you cannot wait the several months that might be needed to control your immediate environment. Environmental control includes washing your pet’s bedding, vacuuming carpets daily, washing area rugs, using Fleabusters powder, and using insecticides (bombs and sprays) inside and outside your home.
Many of the newer oral and topical products kill more than just fleas. They can prevent heartworm, kill mites, and treat internal parasites. For the majority of people, this is the best option. Depending on circumstances, include the degree of infestation, presence of children, your pet’s overall medical status, and how cooperative your pet is, a vet will give some specific recommendations, particularly whether oral or topical medication will work best in your situation.
If your pet has substantial fleas and skin problems during an exam, a vet may administer a short-acting oral medication that kills fleas within a few minutes. When combined with shampooing to remove more fleas and clean the hair coat, your pet will get immediate comfort and the topical medication will get a head start on flea control. It is common for us to provide this treatment while you go home and take care of the environment. You can pick up a flea-free pet and bring it into an environment that has much fewer fleas.
Shampooing gives immediate relief, although the effects are short-lived. Prior to our new safe and effective products, we used to dip pets with an insecticide that was much more toxic than our current products. As a general rule, if your pet only has fleas and no other ectoparasite (i.e., an external parasite like a mite or a tick), we do not usually go this route. The same thing applies to flea powders and sprays.
Flea collars work well on adult fleas, and new ones have residual activity up to eight months. Make sure you put a flea collar in the vacuum bag and empty frequently, or the fleas in the bag will hatch and start the infestation all over again.
An often overlooked and effective flea control mechanism is the common flea comb. When your pet returns from outdoors, spend a few seconds with a flea comb, especially on the lower-back area, to minimize how many fleas it has picked up and to minimize any that are introduced into your house.
Another often overlooked and effective flea-control method is to give a short haircut to longhaired pets during the warmer months. Your pet will feel much more comfortable, and flea control will be easier. In our area, we recommend this haircut in May and again a few months later because fur grows back rapidly. Your pet cares more about what it feels like than what it looks like, so do both of yourselves a big (and effective and nontoxic) favor.