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| − | {{toplink
| + | #REDIRECT[[:Category:Fleas]] |
| − | |backcolour =
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| − | |linkpage =Insecta
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| − | |linktext =INSECTA
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| − | |pagetype=Bugs
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| − | |sublink1=Parasites
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| − | |subtext1=PARASITES
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| − | }}
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| − | <br>
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| − | [[Image: flea.jpg|thumb|right|250px|Robert Hooke's famous flea from Micrographia]] | |
| − | ==Siphonaptera Introduction==
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| − | [[Image:Arthropod classifiation.jpg|thumb|right|150px|Arthropod Classification - copyright nabrown RVC]]
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| − | Fleas are wingless insects that are laterally flattened so can move rapidly through hair and fur. Their hind legs are adapted for jumping. They are of major significance to veterinary practice and will be seen almost on a daily basis at most general practices. | |
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| − | Adult fleas are blood sucking ectoparasites which can cause pruritis, annoyance and anaemia if present in large numbers. [[Skin Immunologic - Pathology#Flea bite hypersensitivity|Flea allergic dermatitis]] can also occur where the animal becomes allergic to the antigens in the flea saliva triggering a hypersensitivity reaction when the flea bites.
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| − | Fleas can also act as intermediate hosts and vectors.
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| − | The terms '''ctenidia''' and '''combs''' can be used interchangably for spines on the head/thorax. Spines on the cheeks are referred to as '''genal''' and spines on the thorax are called '''pronotal''' combs. The presence and location of the chitinous spines are important in differentiating between the different flea species. The chitinous anal struts are also used for identification and help the flea larvae with vigorous motility.
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| − | ==Species of Veterinary Importance==
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| − | ===''Ctenocephalides felis''===
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| − | *Most common flea on cats and dogs
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| − | *Most important flea of veterinary medicine
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| − | *Commonly called the 'cat flea'
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| − | *Can bite humans and other animals
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| − | *Both genal and pronotal commbs present
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| − | *Similar length genal combs
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| − | *Sloping nose
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| − | ===''Ctenocephalides canis''===
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| − | *Not very common
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| − | *Commonly called the 'dog flea'
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| − | *Host specific
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| − | *Both genal and pronotal commbs present
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| − | *Irregular length genal spines
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| − | *Rounded nose
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| − | ===''Ceratophyllus gallinae''===
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| − | *Commonly called the 'poultry flea'
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| − | *Bites humans and other animals
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| − | *Pronotal combs only
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| − | ===''Pulex irritans''===
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| − | *Commonly called the 'human flea'
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| − | *No combs
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| − | *Head rounded anteiorly
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| − | ===''Spilopsyllus cuniculi''===
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| − | *Commonly called the 'rabbit flea'
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| − | *Both genal and pronotal combs present
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| − | *Genal comb obviously oblique
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| − | *Behaviour synchronised with the reproductive cycle of the rabbit
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| − | **Adults spend most of their time off the host taking occasional blood feeds
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| − | **Shortly before the doe gives birth the adult fleas attach to the ears of the rabbit and feed producing a lot of faeces
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| − | **After parturition the adult fleas move onto the kittens where they feed, mate and lay eggs
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| − | **The new adult fleas emerge from the pupa before the kittens leave the nest
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| − | ===Other important flea species===
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| − | *Fleas of wildlife can sometimes infect domestic animals
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| − | *Other species of importance are found in America
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| − | **E.g. ''Tunga penetrans'' or 'Jiggers' which burrows into the skin of man (also called the 'sand flea' or 'chigoe flea')
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| − | *''Nosopsyllus fasciatus''
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| − | **Rodents
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| − | **18-20 spines in pronotal ctenidium
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| − | *''Echisnophaga gallinacea''
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| − | **Poultry
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| − | **Frons (forehead) angled anteriorly
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| − | **Also called the 'sticktight' flea
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| − | *''Archaeopsylla erinacei''
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| − | **Hedgehogs
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| − | **1-3 short spines on genal ctendium
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| − | **1 short spine on pronotal ctenidium
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| − | ==Life-Cycle==
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| − | ''In order to advise owners of adequate treatments to control fleas on their animals, the life cycle of the flea must be understood''
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| − | *The time for the egg to develop into the adult flea takes 3-4 weeks in summer
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| − | *The life cycle can be faster or slower depending on temperature
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| − | '''1. Adults'''
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| − | *Uses changes in light intensity, warmth and carbon dioxide to locate host
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| − | *Once on host, the flea will usually remain
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| − | **With animals in close contact there may be a small degree of transfer between hosts
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| − | **The majority of adult fleas are aquired from the environment
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| − | *The adult flea takes frequent blood meals
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| − | *'''Flea dirt''' (faeces) are produced in large quantities
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| − | *The life span of the flea is determined by the grooming activity of the host
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| − | **Usually the adult flea lives for between 7 and 10 days
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| − | '''2. Eggs'''
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| − | *The adults lay eggs 1-2 days after locating a host
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| − | *Approximately 15 eggs are layed in the pelage (coat) per day
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| − | *Eggs are ivory white and oval, approxiamtely 0.5mm long
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| − | *The eggs drop to the ground within hours
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| − | **In reality this usually happens when the animal jumps of the sofa or makes sudden movements. Flea eggs will cluster in hot spots around the house particularly in places the animal often rests in and this should be considered when control methods are thought about.
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| − | '''3. Larvae'''
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| − | *Larvae are small, about 2-5mm in length
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| − | *Larvae are yellow/white (look like maggots) and are covered in bristles
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| − | *Chitinous mouthparts and anal struts (useful for identification)
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| − | *Larvae are negatively phototropic so try to move away from light sources
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| − | **E.g. under furniture, into thick mats or carpet
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| − | *Larvae feed on skin debris from other animals, flea dirt and other organic debris
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| − | *High humidity is needed to survive
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| − | *Freezing temperatures will kill larvae
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| − | '''4. Pupae'''
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| − | *The larvae pupate forming pupae of 5mm in length
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| − | *Silken cocoon surrounds pupae
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| − | **Slightly sticky so small particles adhere to it
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| − | **Camoflaged in the environment
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| − | *Methoprene the juvenile development hormone coordinates the growth of the immature stages
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| − | **Activates genetic switches
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| − | **Determines the sequence of tissue and organ development
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| − | *Newly emerged adults do not leave the cocoon straight away
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| − | **The '''pupal window''' is the time that it takes for the adult to emerge
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| − | **Temperature determines when the adult fleas emerge
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| − | **Some fleas may wait several months before emerging
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| − | *Newly emerged unfed adults can survive days without feeding but once they have fed, if they fall of the host they can only survive hours
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| − | ==Habitats==
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| − | *Only aproximately 5% of the flea population will be on the animal (and usually it is a much smaller percentage)
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| − | *The rest of the population are in the environment
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| − | **E.g. Eggs, larvae, pupae and unfed adults
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| − | *Fleas accumulate in certain '''hot spots''' where the animal spends the majority of its time
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| − | **E.g. Warm, shady, humid ares
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| − | **E.g. Outdoors in warmer climates or inside in temperate climates
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| − | *Very large numbers of eggs are found in areas where cats land after jumping as they have been dislodged
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| − | **E.g. Beside sofas
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| − | ==Control==
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| − | *Single or occasional treatments will only give temporary relief from fleas as the majority of the population is '''in the environment'''
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| − | *Appropriate action muct be taken to stop re-infestation
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| − | *The animal must be rid of its resident flea population
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| − | *The animal should be protected against subsequent re-infestation
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| − | **From within the home
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| − | **From outside the home
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| − | *The enironmental reservoir population should be eliminated
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| − | **Animal treatment to deplete reservoir
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| − | ***Alduticides
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| − | ***Adulticides with larvicidal effects
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| − | ***Insect growth regulators (IGR's)
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| − | **Direct chemical treatment of domestic environment
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| − | ***Insecticides
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| − | ***Insect growth regulators
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| − | ***Inorganic chemicals
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| − | ***Entomorphagous nematodes
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| − | *To prevent resistance occuring, control methods should not rely solely on chemical methods
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| − | **Hygiene such as regular vaccuming and washing of the animal's bedding should also occur for the most effective treatment
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| − | *For more information on the chemicals used for flea treatment click [[Ectoparasiticides|here]].
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| − | ==Links==
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| − | ''Internal''
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| − | *[[Skin Immunologic - Pathology#Flea bite hypersensitivity|Flea allergic dermatitis (FAD)]]
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| − | *Fleas acts as intermediate hosts for '''Dipylidium tapeworms'''
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| − | *Fleas act as vectors for [[Poxviruses#Myxoma virus|myxomatosis]] in rabbits
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| − | ''External''
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| − | *[http://en.wikipedia.org/wiki/Flea Wikipedia- Fleas]
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