• Treating and Preventing Fleas

    Posted on March 30, 2014 by Dr. Natasha Kassell in fleas and ticks.

    I’m writing this article in March, and thankfully, most fleas have yet to emerge from their eggs and cocoons.  But with warmer months on their way, I find myself considering how to best deal with fleas while causing minimal harm to our pets, ourselves and our environment.

    How fleas happen

    For starters, let’s look at the life cycle of the flea.  Adult fleas spend most of their lives on dogs and cats, feasting, mating and laying hundreds of minute eggs.  The eggs are slippery and slide off the dogs and cats into the environment, concentrating in areas where our pets spend most of their time.  As little as two days after being laid, millimeter-long, worm-like larvae hatch from the eggs.  These larvae burrow into dark places such as carpet, bedding and cracks between floorboards where they spin tiny cocoons, much like butterflies.

    When it’s cool and dry, or when there are no mammals or birds around to feed on, fleas remain in their cocoons for up to two years! During warm, humid months, adult fleas emerge from the cocoons one to two weeks after spinning them.  Other stimuli that signal it’s time to emerge include vibrations and carbon dioxide emitted by warm-blooded animals including dogs, cats and humans.  This is the reason you can enter a house that was inhabited by pets months or even years earlier and suddenly be attacked by hordes of hungry, freshly-hatched fleas.

    How to detect fleas

    Usually it’s obvious: your dog or cat is itching, you see fleas on their underbelly, or you’re getting bitten yourself! But maybe your dog or cat is itchy, or scabby around the tail and you can’t find any fleas. While itchiness can be caused by anything from seasonal allergies to food allergies, chances are they do have fleas.  Fleas can bite and cause itchiness all over the body, but they often congregate and cause the most itching in the tail base region.  This is true for both dogs and cats.

    But how to tell for sure if you’re not actually seeing any fleas?  Start by going to any pet store and purchasing yourself a “flea comb.”  When you get home, dampen a piece of white paper towel or toilet paper with a little water.  Now comes the fun part.  Comb your pet all over.  If the comb picks up anything that resembles dirt, put it on the paper and smudge it with your finger.  Regular dirt remains brown.  Flea “dirt” is actually flea excrement, which contains digested blood.  When moistened, it will smudge a lovely shade of red.  If you find flea dirt, even a little, you can be sure that your pet has at least a few fleas.

    Proactive defense: a strong immune system

    How to combat the voracious little vampires? A strong immune system is the first line of defense.  The immune system is important not only for fighting off internal germs and parasites, but external, as well.  This point was vividly illustrated to me a couple of years ago when my old cat was nearing the end of his life.  He became quite debilitated, and practically overnight, was covered with fleas, poor guy.  Yet I couldn’t find a single flea on our dog, who was young and vibrant.

    There are many factors to consider in supporting your pets’ immune system:

    • A nutritious diet, preferably based on raw or lightly cooked foods, is key.
    • Medications, including vaccinations, should be used sparingly.
    • When possible, choose modalities to treat illnesses that increase the overall health of your pets such as homeopathy, acupuncture and chiropractics.
    • Minimize contact with toxins: exterminator sprays, poisonous cleaning products and topical flea and tick preparations, to name a few.

    Providing your pets with plenty of fresh air, sunshine and exercise is also important.  I realize that for indoor-only cats, this can be difficult to accomplish.  Like dogs, cats can get used to being on a leash.  This is a great compromise that will keep your cats (and neighborhood songbirds) safe while still providing them with some of the benefits of getting outside.

    Nutritional supplements that can help repel fleas include garlic, B-vitamins and fish oil.  Though many people have fed their dogs and cats garlic for years without any problem, its use has become controversial.  Garlic, like onions, contains thiosulfate, which can cause a potentially fatal anemia in dogs and cats.  Use it at your own discretion.  Flea Treats are a chewable product formulated for dogs and cats (not fleas) that contain B-vitamins.  Sea Pet and Nordic Naturals both produce high quality, omega-3 fish oils for pets.

    Manage the indoor environment

    Since approximately 75% of the flea’s lifecycle is spent in the environment in the form of eggs, larvae and pupae in cocoons, treating the environment makes sense.  That said, I do not recommend bombs.  Pesticides released from bombs shoot into the air, landing on couches, countertops and surfaces where pets lie (and children play), yet failing to penetrate the deeper, darker areas where flea larvae burrow and form their cocoons.

    There are several less toxic and more effective solutions for treating the environment.  Vacuum frequently, making sure to discard the vacuum bag after use or the fleas will hatch, crawl out of the bag and waste no time in finding your pets.  Wash all bedding in hot, soapy water and dry on high.  Consider using Flea Buster’s (active ingredient: borate), a powder that you apply to carpet and wood floors.  While relatively nontoxic to mammals, birds and reptiles, this product scratch the exoskeleton of the fleas, causing them to dehydrate and die.

    Topical herbal sprays such as Only Natural Herbal Defense Spray can help repel fleas and ticks.  My concern is that some pets, especially cats, are sensitive to aromatherapy in herbal sprays.  If your pets show any signs of side effects, such as skin irritation or foaming at the mouth, rinse them to remove the spray and discontinue use.

    For short-haired cats and dogs, daily flea combing with a comb made specifically for that purpose is helpful at removing adult fleas.  Keep in mind that you have to kill the fleas quickly or they’ll jump away and quickly find their way back onto your pets.  Squash them between your thumbnails until you hear a satisfying pop, drop them in alcohol or roll them between your fingers until their legs are crushed and they can no longer hop.  Though gruesome, these techniques are effective.

    Treat the yard too

    Frequently, dogs and cats pick up fleas by spending time in infested yards and bringing fleas indoors. It’s thus important to treat outdiirs areas.  There are naturally occurring, microscopic nematodes that kill insect larvae, including fleas.  When applied to soil, they parasitize the larvae and eat them up, yum.  Infected larvae die within two to five days.  The nematodes (a species of roundworm) are harmless to all members of the animal kingdom aside from insects.  They can be purchased in concentrated form through many garden, pet and on-line stores such as Flea Busters.  Keep in mind that if the winter is unusually warm, the fleas will likely be worse the following summer.  To fight a serious flea issue, you’ll have to treat your pets and your home, as well the yard.

    Last resort: chemicals, with caveats

    What if you do all of the above, and your pet still has fleas?  As a last ditch resort, I reach for the big guns such as Frontline, Advantage and Revolution.

    Many veterinarians recommend monthly, year-round application of these spot-on products.  I do not.  These products contain strong pesticides and should be used judiciously.  Here in Philly, it’s almost never necessary to use them year round.  Our toughest flea months tend to be August, September and October.  For most pets, a few fleas are tolerable.  For those who get fleas despite the use of benign methods to repel them and become uncomfortably itchy, one to two doses of a spot-on product, applied at an interval of no less than four weeks, is usually sufficient.

    The other reason spot-on products concern me is that they are dangerous.  They contain potent pesticides that gradually disperse over the skin and collect in the oil-producing sebaceous glands in the skin.  The pesticides are then wicked onto the hair for 30 days or more, killing any fleas that come in contact with them.  But what effects do these pesticides have on the dogs and cats on whom they’re applied, and on the humans, especially the children, who stroke and cuddle their pets?

    Documented acute side effects for dogs and cats include skin irritation, lethargy, hyperactivity, vomiting, diarrhea, muscle tremors, seizures and death.  Long-term effects are unknown, though many spot-on products contain active ingredients that, according to the EPA, are possible or likely carcinogens.  In addition, the ingredients can be lethal to birds, lizards and fish.  Please consider this if your dog likes to swim.

    An alternative to the spot-on products is an oral product called Comfortis.  Comfortis circulates in the blood stream and kills fleas when they ingest a blood meal.  Since it is not concentrated on the skin and hair, I prefer it over the spot-on products, especially if children are interacting with the pets.

    Though not surprising, it’s unfortunate that the most effective flea control products we have are also the most toxic.  Try not to become discouraged.  While fighting fleas can be a challenge, by using an integrated approach, it doesn’t have to be impossible.