Fleas

What are Fleas?

Fleas are insects of which there are 3 main types of fleas as follows:

  • Cat flea (Ctenocephalides felis)
  • Dog flea (Ctenocephalides canis)
  • Human flea (Pulex irritans)

Cat flea(Ctenocephalides felis)

Ctenocephalides felis

The female cat flea lays her eggs on the host, but the eggs, once dry, have evolved to filter out of the hair coat of the host into the resting and sheltering area of the host.  Flea larva showing red ingested blood. The eggs hatch into larvae, which are negatively phototoxic, 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 hair coat of the host after it is deposited there as adult flea faecal material. Thus the adult population on the host feeds the larval population in the host's environment.

Flea faecal material, here combed from a cat, is also called flea dirt Flea larvae metamorphose through 4 stages before spinning a cocoon and entering the pupa stage. The pupa 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.

The female cat flea lays her eggs on the host, but the eggs, once dry, have evolved to filter out of the hair coat of the host into the resting and sheltering area of the host. 

Flea larva showing red ingested blood. The eggs hatch into larvae, which are negatively phototoxic, 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 hair coat of the host after it is deposited there as adult flea faecal material. Thus the adult population on the host feeds the larval population in the host's environment.

Flea faecal material, here combed from a cat, is also called flea dirt Flea larvae metamorphose through 4 stages before spinning a cocoon and entering the pupa stage. The pupa 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.

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. If the fleas have been sucking blood, then they will have a reddish-brown colour when squashed.

Cat fleas can transmit other parasites and infections to dogs and cats and also to humans. The most prominent of these are Bartonella, murine typhus, and apedermatitis. The tapeworm Dipylidium caninum can be transmitted when a flea is swallowed by pets or humans. In addition, cat fleas have been found to carry Borrelia  Burgdorferi, the etiologic agent of Lyme disease, but their ability to transmit the disease is unclear.

Dog flea(Ctenocephalides canis)

The dog flea's mouthparts are adapted for piercing skin and sucking blood. Dog fleas are external parasites, living by haematophagy off the blood of dogs. The dog often experiences severe itching in all areas where the fleas may reside.

Fleas do not have wings and their hard body is flattened from side-to-side and has hairs and spines, which makes it easy for them to travel through hair. They have relatively long hind legs for jumping. Flea infestations can be not only annoying for both dogs and humans but also very dangerous. Problems caused by fleas may range from mild to severe itching and discomfort to skin problems and infections. Anaemia may also result from flea bites in extreme circumstances. Furthermore, fleas can transmit tapeworms and diseases to pets.

When fleas bite humans they may develop an itching rash with small bumps that may bleed. This rash is usually located on the armpit or fold of a joint such as the elbow, knee, or ankle. When the area is pressed, it turns white. When dogs are troubled by fleas they scratch and bite themselves especially in areas such as the head, neck, and around the tail. Fleas normally concentrate in such areas. This incessant scratching and biting may cause the dog's skin to become red and inflamed.

Flea allergy dermatitis is developed by those dogs allergic to flea saliva. In this case, the symptoms previously mentioned are more pronounced. Because of compulsive scratching and biting, the dog may lose hair, get bald spots, exhibit hot spots due to extreme irritation, and develop infections that result in smelly skin.

Too effectively get rid of fleas and flea eggs, one should treat not only dogs but also the household and exterior regions to eliminate eggs from bedding, grass, floor, furniture and other areas.

Treatment should be given as soon as signs of fleas appear and repeated regularly. Delays in treating the infestation may lead to flea-transmitted diseases.

Once-a-month topical products are the most commonly used products to kill parasite infestations. They are normally applied on the back of the pet and their advantage is that they also provide protection from further infestations. Sprays come in the form of aerosols and pump bottles and they are meant to be applied on all parts of the pet. Dips and rinses are also available but they are not as common as the other such products because they are ones of the most unsafe for the health of the pet.

In 2009 the Environment Protection Agency (EPA) conducted an investigation into the reactions of many pets to topical flea products and released preliminary reports in the spring of 2010.

There are also different treatments available for dogs from natural alternatives to chemically-based products that include topical medications and oral medications. Although common remedies provide natural options with natural ingredients such as lavender, pennyroyal, neem, and sweet mace which are insect repellents care should be used since "natural" does not always mean non-toxic.

Evaluations of the toxicity of flea treatment products have been scientifically studied and are available online from the Natural Resource Defence Council [8] and a list of less toxic and alternative treatments can be found in the reference book, Flea Control Secrets which maintains a blog specifically on flea treatment. Control products include medicines, drops and sprays that offer different results. Some of the most common brands and their basic characteristics include:

  • Frontline comes in sprays, drops, general flea medication and other flea control products and it is highly effective.
  • Advantage is a quick-acting topical application product that stops biting fleas in three to five minutes.
  • K9 Advantix not only kills fleas and ticks but also offers control against mosquitoes, biting flies and lice with its waterproof formula.
  • Capstar is an affordable Nitenpyram pill that kills 98% of adult fleas within five hours. However, eggs and larva do not get killed so it may be necessary to combine it with another product.
  • Program comes in pills or liquid and it is taken monthly. It basically kills off the flea's capacity to reproduce which gradually kills off all the fleas.
  • Revolution is a spot application that protects dogs from heartworms, fleas and other parasites.
  • Biospot is an affordable option made to kill fleas, ticks, and mosquitoes. One application lasts about three months for fleas but one month for ticks and mosquitoes. It is not waterproof.
  • Sentinel is a monthly Lufenuron tablet that stops young fleas from moulting their outer shells, and makes the females lay eggs that can't hatch.

Before choosing a treatment it is important to know the dog's weight and age. It is also important to consult a veterinarian to learn more about the products and choose the one that is best for the dog. Alternative treatments include homemade repellents. Garlic is also thought to be effective in repelling fleas, when eaten as well as apple cider vinegar diluted in water.

Tests proved that they do not work. The word of mouth of them working is merely a placebo effect.

Human flea(Pulex irritans)

The human flea, Pulex irritans, is a cosmopolitan flea species that has, in spite of the common name, a wide host spectrum. It is one of six species in the genus Pulex; the other five are all confined to the Nearctic and Neotropical regions. The species is thought to have originated in South America, where its original host may have been the guinea pig or peccary.

This species bites many species of mammals and birds, including domesticated ones. It has been found on dogs and wild canis, monkeys in captivity, opossums, domestic cats, wild felids in captivity, chickens, black rats and Norwegian rats, wild rodents, pigs, free-tailed bats, and other species. It can also be an intermediate host for the cestode, Dipylidium caninum.

The human flea, Pulex irritans, is a cosmopolitan flea species that has, in spite of the common name, a wide host spectrum. It is one of six species in the genus Pulex; the other five are all confined to the Nearctic and Neotropical regions. The species is thought to have originated in South America, where its original host may have been the guinea pig or peccary.

This species bites many species of mammals and birds, including domesticated ones. It has been found on dogs and wild canis, monkeys in captivity, opossums, domestic cats, wild felids in captivity, chickens, black rats and Norwegian rats, wild rodents, pigs, free-tailed bats, and other species. It can also be an intermediate host for the cestode, Dipylidium caninum.

Appearance

Fleas are black to brownish–black wingless insects. Adult fleas are 1 to 4 mm long.  They possess a long, fine proboscis which is used to pierce the skin of their host to feed on their blood.  They have a characteristic jumping movement.

Lifecycle

A female flea will lay 4 to 8 eggs after each blood meal, and can usually lay several hundred eggs during her adult life. The smooth, oval light–coloured eggs measuring around 0.5 mm long, are deposited on, but not firmly attached to, the body, bedding, or nest of the host. The adult generally emerges in a week or two after completing a larval and pupa stage, but under unfavourable conditions, the pupa period may be as long as a year.

Habits

Fleas most often bite people around the legs and ankles, usually with 2 or 3 bites in a row. The bites are felt immediately and can be sore for as much as a week. Since they move from one host species to another, they present a risk of transmitting disease. Pulex irritans is also a vector of Yersinia pestis (plague).  Human fleas can also be found on animals such as dogs, rats, pigs, deer and foxes.

The above information has been sourced from wiki pages and government advice web sites.

Back to Pest Control and Infestations