INFESTATION BY FLEAS
Fleas are small insects that appear flattened from side to side. They have piercing mouthparts and infest the hair coats of mammals and plumage of birds. Over 2,400 different species exist worldwide; fortunately, only a few species are important to humans. The side-to-side flattening of fleas bodies and their stiff bristle hairs, or setae, allow fleas to move quickly and make them difficult to remove from hair coats of pets Some well known flea species include: • • • • • Cat flea (Ctenocephalides felis), Dog flea (Ctenocephalides canis), Ηυµαν φλεα (Pulex irritans), Northern cow flea (Nosopsyllus fasciatus), Οριενταλ ρατ φλεα (Xenopsylla cheopis
Life cycle and habitat
Fleas are holometabolous insects, going through the three life cycle stages of larva, pupa, and imago (adult). The flea life cycle begins when the female lays after feeding. Adult fleas must feed on blood before they can become capable of reproduction. Eggs are laid in batches of up to 20 or so, usually on the host itself, which easily roll onto the ground. As such, areas where the host rests and sleeps become one of the primary habitats of eggs and developing fleas. The eggs take around two days to two weeks to hatch. Once the flea reaches adulthood its primary goal is to find blood - adult fleas must feed on blood in order to reproduce. Adult fleas only have around a week to find food once they emerge, though they can survive two months to a year between meals. A flea population is unevenly distributed, with 50 percent eggs, 35 percent larvae, 10 percent pupae, and 5 percent adults. Their total life cycle can take as little as two weeks, but may be lengthened to many months if conditions are favorable. Female fleas can lay 500 or more eggs over their life, allowing for phenomenal growth rates. Adult female rabbit fleas, Spilopsyllus cuniculi, can detect the changing levels of cortisol and corticosterone, hormones in the rabbit's blood that indicate she is getting close to giving birth. This triggers sexual maturity in the fleas and they start producing eggs. As soon as the baby rabbits are born, the fleas make their way down to them and once on board they start feeding, mating, and laying eggs. After 12 days, the adult fleas make their way back to the mother. They complete this mini-migration every time she gives
birth.[5 Once the flea reaches adulthood its primary goal is to find blood - adult fleas must feed on blood in order to reproduce. Adult fleas only have around a week to find food once they emerge, though they can survive two months to a year between meals. A flea population is unevenly distributed, with 50 percent eggs, 35 percent larvae, 10 percent pupae, and 5 percent adults. Their total life cycle can take as little as two weeks, but may be lengthened to many months if conditions are favorable. Female fleas can lay 500 or more eggs over their life, allowing for phenomenal growth rates. Adult female rabbit fleas, Spilopsyllus cuniculi, can detect the changing levels of cortisol and corticosterone, hormones in the rabbit's blood that indicate she is getting close to giving birth. This triggers sexual maturity in the fleas and they start producing eggs. As soon as the baby rabbits are born, the fleas make their way down to them and once on board they start feeding, mating, and laying eggs. After 12 days, the adult fleas make their way back to the mother. They complete this mini-migration every time she gives birth.[5 Relationship with host Fleas attack a wide variety of warm-blooded vertebrates including dogs, cats, humans, chickens, rabbits, squirrels, rats, ferrets, and mice. Fleas are a nuisance to their hosts, causing an itching sensation which in turn may result in the host attempting to remove the pest by biting, pecking, scratching, etc. the vicinity of the parasite. Fleas are not simply a source of annoyance, however. Some people and animals suffer allergic reactions to flea saliva resulting in rashes. Flea bites generally result in the formation of a slightly-raised swollen itching spot with a single puncture point at the center. The bites often appear in clusters or lines of two bites, and can remain itchy and inflamed for up to several weeks afterwards. Fleas can also lead to hair loss as a result of frequent scratching and biting by the animal, and can cause anemia in extreme cases. Besides the problems posed by the creature itself, fleas can also act as a vector for disease. For example, fleas transmitted the bubonic plague between rodents and humans by carrying Yersinia pestis bacteria. Murine typhus (endemic typhus) fever, and in some cases Hymenolepiasis (tapeworm) can also be transmitted by fleas. Flea treatments
The itching associated with flea bites can be treated with anti-itch creams, usually antihistaminics or hydrocortisone. Calamine lotion has been shown to be ineffective for itching.
The fleas, their larvae, or their eggs can be controlled with insecticides. Lufenuron is a veterinary preparation (Program) that attacks the larval flea's ability to produce chitin but does not kill fleas. Flea medicines need to be used with care as many, especially the
acetylcholinesterase inhibitors, also affect mammals. Popular brands of topicals that do not contain cholinesterase inhibitors include Advantage, Advantix, and Frontline and Frontline PLUS. In 2008, three next-generation flea products reached the market: Promeris, Comfortis, and Vectra 3D.
For the home
Combating a flea infestation in the home takes patience as for every flea found on an animal there are many more developing in the home. A spot-on insecticide, such as Advantage, Frontline, or Revolution will kill the fleas on the pet and in turn the pet itself will be a roving flea trap and mop up newly hatched fleas. The environment should be treated with a fogger or spray insecticide containing an insect growth regulator, such as pyriproxyfen or methoprene to kill eggs and pupae, which are quite resistant against insecticides. Frequent vacuuming is also helpful, but you must immediately dispose of the vacuum bag afterwards Diatomaceous earth can also be used as an effective home flea treatment in lieu of acetylcholinesterase inhibitory treatments or insecticides which carry with them a risk of poisoning for both humans and animals. Diatomaceous earth absorbs lipids from the cuticle, the waxy outer layer of insects' exoskeletons, causing them to dehydrate. Purchasable from most gardening suppliers or online retailers, it can be evenly distributed around the house (especially in corners and near furniture) with any type of shaker (salt shaker, spice shaker, etc.) and then vacuumed away after about 7 days. Diatomaceous earth also has the added benefit of killing many other types of insects that might be residing in your house. Dried pennyroyal has been suggested as a natural flea control, but is not recommended in homes with pets due to its high toxicity to mammals. Borax is sold as a "Natural Laundry Booster" and can also be used as another home treatment for flea infestations. Borax contains boric acid which kills fleas by dehydrating them. Using dehumidifiers with air conditioning and vacuuming all may interrupt the flea life cycle. Humidity is critical to flea survival. Eggs need relative humidity of at least 70-75 percent to hatch, and larvae need at least 50 percent humidity to survive. In humid areas, about 20 percent of the eggs survive to adulthood; in arid areas, less than five percent complete the cycle. Fleas thrive at higher temperatures, but need 70° to 90°F to survive. Lower temperatures slow down or completely interrupt the flea life-cycle. A laboratory study done at the University of California showed that vacuuming catches about 96 percent of adult fleas. A combination of controlled humidity, temperature, and vacuuming should eliminate fleas from an environment, and altering even one of these environmental factors may be enough to drastically lower and eliminate an infestation. Antipruritics, also known as anti-itch drugs, are medications that inhibit the itching (Latin: pruritus) that is often associated with sunburns, allergic reactions, eczema,
psoriasis, chickenpox, fungal infections, insect bites and stings like those from mosquitoes, fleas, and mites, and contact dermatitis and urticaria caused by plants such as poison ivy (urushiol-induced contact dermatitis) or stinging nettle.
Topical antipruritics in the form of creams and sprays are often available over-thecounter. Oral anti-itch drugs also exist and are usually prescription drugs. The active ingredients usually belong to the following classes: • • • • • Antihistamines such as diphenhydramine (Benadryl) Χορτιχοστεροιδσ such as hydrocortisone topical cream, see topical steroid Λοχαλ ανεστηετιχσ such as benzocaine topical cream (Lanacaine) Χουντεριρριταντσ, such as mint oil, menthol, or camphorHYPERLINK \l "cite_note-Hercogova-0"
The cat flea's primary host is the domestic cat, but this is also the primary flea infesting dogs in most of the world. The cat flea can also maintain its life cycle on other carnivores and on the Virginia opossum. Rabbits, rodents, ruminants and humans can be infested or bitten, but a population of cat fleas cannot be sustained by these aberrant hosts.
The female cat flea lays her eggs on the host, but the eggs, once dry, have evolved to filter out of the haircoat of the host into the resting and sheltering area of the host. The eggs hatch into larvae, which are negatively phototaxic, meaning that they hide from light in the substrate. Flea larvae feed on a variety of organic substances, but most importantly subsist on dried blood that is filtered out of the haircoat of the host after it is deposited there as adult flea fecal material. Thus the adult population on the host feeds the larval population in the host's environment. Flea larvae metamorphose through 4 stages before spinning a cocoon and entering the pupal stage. The pupal stage varies greatly in length; the pre-emergent flea does not normally emerge as a young adult flea until the presence of a potential host is perceived by warmth or vibration. Newly emerged fleas are stimulated to jump to a new host within seconds of emerging from the cocoon. The new flea begins feeding on host blood within minutes
Effects on the hosts
A few fleas on adult dogs or cats cause little harm unless the host becomes allergic to substances in saliva. The disease that results is called flea allergy dermatitis. Small animals with large infestations can lose enough bodily fluid to fleas feeding that dehydration may result. Fleas are also responsible for disease transmission through humans.
Cat fleas can transmit other parasites and infections to dogs and cats and also to humans. The most prominent of these are Bartonella, the tapeworm Dipylidium caninum, murine typhus, and apedermatitis. FLEAS Fleas are blood-sucking insects that feed on humans, dog, cats, and other animals. Fleas do not have wings.Causes Fleas prefer to live on dogs and cats, but may also be found on humans and other available animals. Pet owners may not be bothered by fleas until their pet is gone for a lengthy period of time, and the fleas must find another place to go. This is when they begin to bite humans. Bites frequently occur around the waist, ankles, armpits, and in the bend of the elbows and knees.
• • • • Hives Itching can be all over or just where the rash is Itching can be severe Ραση with small bumps that itch and may bleed • • • • • Located on the armpit or fold of a joint (at the elbow, knee, or ankle) The amount of skin affected increases over time (enlarging skin rash or lesion) or the rash spreads to other areas When pressed the area turns white (blanches to touch)
Skin folds such as under the breasts or in the groin may be affected (intertrigo) Swelling only around a sore or injury
Note: Symptoms often begin suddenly (within hours).
Exams and Tests
No testing is necessary.
The goal of treatment is to get rid of the fleas by treating the home, pets, and outside areas with insecticide. Small children should not be in the home when insecticides are being used. Birds and fish must be protected during spraying. Home foggers and flea collars do not always work. If home treatments do not work, professional extermination may be needed. If flea bites occur, an over-the-counter 1% hydrocortisone cream can help relieve itching.
Getting rid of fleas can be difficult and takes persistence.
Scratching can lead to a secondary skin infection.
Prevention may not be possible in all cases. Use of insecticides may be helpful if fleas are common in your area. Professional extermination may be necessary in some cases.
The fastest flea treatment method is to give your pet a flea bath. Flea baths are common treatments for dog owners however as cat owners will attest to, its very hard to get a cat into water. In addition to flea baths, pet owners can also also use another form of flea treatment called a flea shampoo. A flea shampoo is as its name implies. Again, flea shampoos are usually used by dog owners.
Risk factors and detection All pets are at risk for a flea infestation. Pets who spend time outdoors are particularly susceptible. Why? Many adult fleas live outside and on wildlife hosts until they find a happy home on your pet. Indoor dogs also are at risk because they can pick up fleas when they go outside to exercise or eliminate. Signs of flea infestation include: • • flea feces, or pepper-like specks, in your pet's coat or on his bedding flea eggs, or light-colored specks, in your pet's coat or on his bedding
• • • • •
itchy skin (scratching) biting at his fur or legs patchy hair loss, especially near the tail or neck lethargy (especially in severe cases) tiny, dark brown insects scurrying around on your pet.
Prevention and treatment Several products kill adult fleas on your pet, while others upset the flea life cycle. Some common prescription products include: Program. This monthly flea preventive comes in a tablet for dogs. Program uses an insect growth inhibitor to prevent development of eggs and larvae, but it doesn't kill adult fleas. Sentinel. This product, available only for use in dogs, contains the same active ingredient for flea prevention as Program but also includes a heartworm preventive and intestinal dewormer. Advantage and Frontline. These topical liquid products for dogs kill adult fleas, thereby disrupting the egg-laying stage. You simply apply a small amount of liquid on the skin between your pet's shoulder blades. Frontline also kills ticks. Revolution. This topical product for dogs kills adult fleas, prevents flea eggs from hatching, and treats or controls several other parasites, including heartworm. You can purchase other flea-control products—powders, sprays, collars, and dips—overthe-counter, but veterinarian-prescribed treatment methods are safer, more effective, and easier to use. Treating the environment Once fleas invade your home, you must treat both your pet and the environment. You can try environmental foggers, which release insect growth inhibitors to control eggs, larvae, and adults, but you must repeat the treatment about three weeks later to kill any newly hatched adults that beat the bomb. Never use environmental treatments on your pet. Don't skimp on this stage! You'll only set yourself up for failure. The most effective but also most costly option: professional exterminators. It's easy—no labor on your part— and most exterminators offer a guarantee. Treating flea allergy dermatitis FAD isn't life-threatening, but it can be very uncomfortable and can cause severe biting, chewing, and licking. FAD usually manifests on the back half of the body, but some pets develop sensitivity on their front legs. All this scratching and chewing can cause sores and patchy hair loss—giving your formerly fluffy pet a rundown appearance. Your veterinarian can prescribe steroids to relieve the itch. Treatment often starts with an
injection followed by daily tablets for a few weeks. Your veterinarian will reduce the dosage slowly to prevent adverse effects from abrupt withdrawal. Steroid side effects include increased thirst, which means increased urine output as well. Occasionally pets may urinate in the house, but these side effects will decrease as the steroid dosage decreases. Call your veterinarian if you have any concerns about side effects. Secondary skin infections can develop from all that scratching. Your veterinarian will prescribe appropriate antibiotic therapy. Once antibiotic treatment begins and the intense itching stops, the secondary infection quickly resolves and your pet's coat grows back fairly quickly. Prognosis FAD symptoms improve with steroid treatment, but they can recur if you don't permanently eliminate fleas from your pet and home environment. Most pets who suffer flea bite anemia will recover without side effects if treated promptly. If your pet has fleas, ask your veterinarian about the risk of tapeworms. You can avoid the hassle of treatment and discomfort—and stop fleas in their tracks— with an aggressive flea control program. Talk to your veterinarian about which products are right for you. www.petfleameds.com www.fleabuster.com