Microscopic image of a flea
Photo by E. Pollard/PhotoLink/Getty Images
About the Flea:
The Life Cycle of Fleas:
- Egg: An adult female flea can lay up to 40 eggs a day. The eggs are laid on the host, but will dry and fall off that host into the environment (pet bedding, carpet, etc). Eggs typically hatch within about two days.
- Larva: When the eggs hats, larvae emerge. These tiny worm-like creatures feed upon flea feces (basically dried animal blood) in the environment. The larva goes through three molts before it becomes able to spin a cocoon and enter the pupal stage. The larval stage typically lasts from 5 to 15 days.
- Pupa: Once in the cocoon, the larva begins its transformation into the adult flea. The cocoons are nearly indestructible and attract dirt and debris that camouflage them. Pupa can remain dormant in the environment for many months. Fleas in the pupa stage will not emerge until they sense a host. They are able to do this by sensing factors like warmth, vibration and carbon dioxide
- Adult flea: A fully-developed flea only emerges from its cocoon when a host is available. The newly-emerged flea jumps on the host right away and begins the blood meal. A female flea will begin to lay eggs within 24-48 hours of her first blood meal. She defecates blood from her host that will fall off the host along with the eggs, re-starting the life cycle. Adult fleas can live for about 4-6 weeks depending on the environment.
The Dangers of Fleas:
- Flea Allergic Dermatitis: Itching due to fleas is the result of a localized allergic reaction. Some animals are more sensitive than others, so flea bites can lead to severe itching, irritation, major skin infections in some pets.
- Tapeworm infection (Dipylidium caninum): This type of tapeworm can be contracted by animals or humans after accidental ingestion of an infected flea. Flea larva often ingest the microscopic tapeworm eggs, causing adult fleas to be carriers.
- Anemia: If enough fleas infest the host, it is possible for the host animal to lose enough blood to become anemic. Small puppies and weak or sickly dogs are especially at risk. If not caught soon enough, a dog can easily die or suffer other medical complications as a result of anemia.
How to Find Fleas:
If you suspect you have a flea problem, you probably do. For every flea you see, there are probably 50 you don’t see. If you have flea bites on yourself, remember that humans are not ideal hosts and imagine how many bites your pets likely have.
The best way to detect fleas is by using a flea comb. The teeth on these small combs are very close together and designed to travel through hair, picking up everything on the coat. Use the comb all over your dog’s body, but pay close attention to the lower back around the tail, as this is a common “flea-zone.”
If you find no fleas but do see tiny pieces of black debris, this may be flea dirt. Flea dirt is the fecal material of fleas and consists mainly of dried animal blood. On close examination, flea dirt will have a reddish-black appearance. To confirm it is actually flea dirt, try putting the debris on a white paper towel and wetting it slightly. You will see that it runs reddish-brown.
Flea Treatment and Prevention:
When it comes to fleas, prevention is the the best method. However, when fleas are detected, swift action will help prevent a major infestation. Fortunately, in this day and age, even a major infestation can be dealt with.
Flea prevention is seen in many forms. Some work better than others. Some work well together, while onther work against one another and should not be used at the same time. Be sure to talk to your vet about the best options for you and your pet.
- “Spot-On” topical treatments like Advantage and Frontline are distributed in the dog’s natural skin oils and work to kill adult fleas. Some have additional ingredients that sterilize fleas. Typically, the spot-on treatments need to be applied monthly. They are usually water-resistant, meaning you can bathe your dog with a mild shampoo 3 or more days after applying the product. No more than one type of topical treatment should be used at the same time. However, a topical treatment can sometimes be used in conjunction with an oral treatment.
- Oral flea prevention/treatment releases a chemical into the dog’s bloodstream that affects the flea once it bites the dog. Some (like Program and Sentinel) simply cause the flea to become sterilized. Others actually kill the flea (like Comfortis and Capstar). These products are typically given once a month, with the exception of Capstar (which only lasts 48 hours). No more than one type of oral treatment should be used at the same time. However, certain oral treatments can sometimes be used in conjunction with a topical treatment.
- Shampoos, dips and topical sprays designed to kill fleas often work fine when it comes to removing fleas from your dog at that moment, but they rarely last longer than a day or so. When your dog is again exposed to newly-emerged fleas, he will easily become re-infested. Flea shampoos, dips and sprays should not be used in conjunction with topical spot-on treatments, as they may cancel each other out or even cause chemical toxicity.
- Flea collars are relative ineffective. They might kill some fleas around the area of the collar, but rarely prevent the fleas from jumping on other parts of the pet.
For more complete information about flea control products, see these descriptive flea product comparison charts.
Treating the Environment
Three out of four stages in the flea’s life cycle are spent off of the host. Usually the eggs, larvae and pupae are in your carpets, upholstery and pet bedding. In order to prevent infestations (and especially re-infestations) it is important to treat the environment for fleas.
Once you have treated your dog with one of the above, the next thing you’ll need to do is clean your home thoroughly. Machine wash as much as you can in hot water, using bleach when possible. Thoroughly vacuum the carpets and floors, immediately emptying the dust bin or discarding the bag outside. For better results, try sprinkling boric acid on carpets and upholstery. Let it sit for an hour or more, then thoroughly vacuum. Boric acid desiccates flea eggs, larva and pupae, making it easier to vacuum them up.
Flea bombs and household sprays are typically not necessary, though some prefer them for major infestations. Remember that the host (your dog) is what allows the fleas to continue the life cycle. Treating your dog with affective flea prevention is the most important measure.
Some people choose to also treat the exteriors of their homes and yards for fleas. When doing so, please remember to use products deemed non-toxic to dogs. Because of the flea life cycle, exterior treatment should be done once a week for four weeks, then monthly for maintenance. Remember that your dog may still pick up random fleas.
Natural Flea Prevention
For ages, people have tried to come up with home remedies and natural products to ward off fleas. While natural remedies are useful for a number of issues, generally flea treatment is not one of them.
Some say a bit of garlic in the diet helps to prevent flea infestations. In reality, this is not typically affective. In addition, excess garlic in the diet can lead to toxicity for some dogs. Another natural method is the use of essential oils on the pet’s skin and coat. Unfortunately, there is not sufficient documented evidence regarding the effectiveness of this method.
If you choose to go the natural method, just remember three things: 1) Take care not to poison your pet. 2) Know when to give up; if you have an infestation, it’s time to move on to the chemicals. 3) Talk to your vet about the best options for your pet. Above all, keep in mind that a flea infestation is more than just a nuisance – it is a risk to your dog’s health.