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 english myiasis = flies , worms into animals

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Date d'inscription : 17/05/2007

MessageSujet: english myiasis = flies , worms into animals    Dim 19 Mai - 16:11

august 1st 2010

Fleas and Rabbits

Esther van Praag Ph.D.

Fleas can plague rabbits as well as humans. Wild rabbits are mainly infested by the rabbit flea Spilopsyllus cuniculi. The lifecycle of Spilopsyllus cuniculi is synchronized to the lifecycle of the wild rabbit in such a way that eggs are laid after the birth of newborn rabbits. The female flea deposits her eggs inside the nest, where the necessary humidity is present for their development. The survival of the hatched larvae can only happen when humidity is higher than 50%. They feed on the feces of the adult fleas, which are rich in blood sucked from the host.
The flea population infesting a rabbit is composed of eggs (50%), larvae (35%), pupas (10%) and only 5% adults. The development of the fleas is quick and will infest new rabbits.
The length of the lifecycle depends on the humidity of the air and the temperature. In general it lasts between 12 and 14 days, but can take as long as 6 months. Inside a house or an apartment, the complete life cycle takes between 9 days and 4 weeks’ time.

Farmers Bulletin 1568 – bureau of Animal Industry; M.W. Meek, Diseases and Parasites of Rabbits and their control

Spilopsyllus cuniculi, the rabbit flea

Farmers Bulletin 1568 – bureau of Animal Industry; M.W. Meek, Diseases and Parasites of Rabbits and their control

Echinnophaga gallinacea, the chicken flea that can also infest rabbits

Various species of fleas have been found on rabbits. They include Pulex irritans, Cediopsylla simples, Odontopsyllus multispinosus, Echinnophaga gallinacea, or Echidnophasis mymecobil. Domestic rabbits are commonly infested by the cat or dog fleas: Ctenocephalides felis or Ctenocephalides canis, respectively.

The presence of Ctenocephalides felis can cause serious irritation in animals and man. It may be couple with an allergic reaction against the anti-coagulase enzyme present in the injected saliva of the flea. This enzyme is necessary to keep the fleabite open to allow a continuous flow of fresh blood to the flea.

www.biotec-baden.de/tiere.html

Cat flea, Ctenocephalides felis

www.biotec-baden.de/tiere.html

Dog flea, Ctenocephalides canis

Fleas can be carrier of contagious diseases, e.g., myxomatosis, or tularemia, and of tapeworm species specific to the rabbit. The rabbit flea Spilopsyllus cuniculi can transmit dangerous diseases or parasites affecting the wild rabbit population to pet rabbits, such as the viral agent causing myxomatosis or the rabbit protozoan parasite Trypanosoma nabiasi.

Clinical signs and diagnosis
The presence of fleas is typically subclinical and seasonal, with a peak observed at the end of the summer. Infestation is characterized by the presence of the feces of the fleas and their eggs in the fur, or on a flea comb.

Jen Smuck

Presence of flea dirt in the fur and a red spot on the skin of a rabbit is indicative of the presence of fleas.

MediRabbit

Flea comb

The presence of fleas is frequently observed at the periphery of the ears, between them, on the eyelids or the nose of the rabbit. Other locations on the body should nevertheless not be ruled out. In rare cases, a strong allergic reaction against the saliva injected by the flea takes place. If such a reaction is observed, it is recommended to examine the rabbit for further skin disease.

The presence of Spilopsyllus cuniculi often leads to pruritic skin and the appearance of crusts.

Fleabites can be accompanied by secondary bacterial infections. Systemic antibiotics are indicated. A bacterial culture, followed by a sensitivity test, will help determine the best antibiotic option.

Treatment
It is important to treat both the rabbit infested by fleas, other pet animals in the household, and the environment.

Fleas are eliminated by sprays, powder products or topical products:

• pyrethrin based products.

• selamectin: Revolution® (US) or Stronghold® (Europe) - Pfizer, 18 mg/kg. A single topical (local) dose should be sufficient; if not, repeat in 30 days.

• imidacloprid: Advantage® - Bayer, one single application is generally sufficient to remove the fleas. If this is not the case, the treatment can be repeated after 30 days. The vapors of this product can lead to irritation of the eyes; it is thus recommended to aerate the room where the rabbit lives in.

• lufenuron: Program® - Novartis, 10 mg/kg. One sole treatment should be sufficient. If not, the treatment can be repeated after 30 days.

Impregnated anti-flea collars should never be used in rabbits. They lead to severe irritation and burning of the skin. There are reported cases, where the rabbit attempted to remove its collar, and died as a result of jamming its jaw in the collar.

Treatment of the environment is important (boric acid such as Fleabusters®; Vet-Kem Acclaim Plus® - Sanofi; Staykil® - Novartis; Indorex® - Virbac; acaricide spray). When treating a carpet, vacuum first in order to further penetration of the spray or powder. Shampooing and steam cleaning are not ideal; their residual humidity can increase the mite problem. During treatment of the environment, rabbits should be kept in another part of the home to avoid the danger of contact with the products.

For detailed information on flea infestation in rabbits,

see: “Skin Diseases of Rabbits”, by E. van Praag, A. Maurer and T. Saarony

408 pages, 2010.

Further Readings
Amin OM. Comb variations in the rabbit flea, Cediopsylla simplex (Baker). J Med Entomol. 1974;11:227-230.

Farlow JE, Burns EC, Newsom JD. Seasonal distribution of some arthropod parasites of rabbits in Louisiana. J Med Entomol. 1969;6:172-174.

Graves GN, Bennett WC, Wheeler JR, Miller BE, Forcum DL. Sylvatic plague studies in southeast New Mexico. II. Relationships of the desert cottontail and its fleas. J Med Entomol. 1978;14:511-522.

Gurycova D. First isolation of Francisella tularensis subsp. tularensis in Europe. Eur J Epidemiol. 1998; 14:797-802.

Hutchinson MJ, Jacobs DE, Bell GD, Mencke N. Evaluation of imidacloprid for the treatment and prevention of cat flea (Ctenocephalides felis felis) infestations on rabbits. Vet Rec. 2001; 148(22):695-696.

Launay H. On the phenology of the flea Xenopsylla cunicularis Smit, 1957 (Siphonaptera, Pulicidae) parasite of the European rabbit. Ann Parasitol Hum Comp. 1982;57(2):145-163.

Mead-Briggs AR, Vaughn JA, Rennison BD. Seasonal variation in numbers of the rabbit flea on the wild rabbit. Parasitology. 1975;70(1):103-118.

Merchant JC, Kerr PJ, Simms NG, Robinson AJ. Monitoring the spread of myxoma virus in rabbit Oryctolagus cuniculus populations on the southern tablelands of New South Wales, Australia. I. Natural occurrence of myxomatosis. Epidemiol Infect. 2003; 130(1):113-121.

Osacar-Jimenez JJ, Lucientes-Curdi J, Calvete-Margolle C. Abiotic factors influencing the ecology of wild rabbit fleas in north-eastern Spain. Med Vet Entomol. 2001;15(2):157-66.

Osacar JJ, Lucientes J, Calvete C, Peribanez MA, Gracia MJ, Castillo JA. Seasonal abundance of fleas (Siphonaptera: Pulicidae, Ceratophyllidae) on wild rabbits in a semiarid area of northeastern Spain. J Med Entomol. 2001; 38(3):405-410.

Pfaffenberger GS, Valencia VB. Ectoparasites of sympatric cottontails (Sylvilagus audubonii Nelson) and jack rabbits (Lepus californicus Mearns) from the high plains of eastern New Mexico. J Parasitol. 1988; 74(5):842-6.

Pinter L. Leporacarus gibbus and Spilopsyllus cuniculi infestation in a pet rabbit. J Small Anim Pract. 1999; 40(5):220-221.

Rothschild M. Myxomatosis and the rabbit flea. Nature. 1965; 207(2):1162-1163.

Shepherd RC. Myxomatosis: the occurrence of Spilopsyllus cuniculi (Dale) larvae on dead rabbit kittens. J Hyg (Lond). 1978; 80(3):427-9.

Timm KI. Pruritus in rabbits, rodents, and ferrets. Vet Clin North Am Small Anim Pract. 1988; 18(5):1077-91.

Vashchenok VS, Shuliat'ev AA. Spilopsyllus cuniculi fleas--parasites of the wild rabbit on the territory of the USSR. Parazitologiia. 1990; 24(2):148-51.

e-mail: info@medirabbit.com


Dernière édition par végétalienne-13 le Dim 19 Mai - 16:17, édité 2 fois
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MessageSujet: Re: english myiasis = flies , worms into animals    Dim 19 Mai - 16:12

march the 8th of 2010

Myiasis (fly-strike) in Rabbits

Esther van Praag Ph.D.

Warning: this file contains pictures and videos that may be distressing for people.

Myiasis, also called fly-strike, is more frequently observed during the hot humid summer months. It is caused by several kinds of insects that lay their eggs in the wounded skin of mammals. Rabbits suffer in particular from the blowflies Lucilia sericata, Calliphora sp., the grey flesh fly Wohlfahrtia sp., the common screwworm fly Callitroga sp., and from the botfly Cuterebra sp, which is seen in the USA only. A maggot attack is often linked to poor hygiene, with rabbits kept on litter soiled with urine and excrements, or poor-cleaned litter pans, but can also relate to health problems. A particular attention must also be given to rabbits suffering from dental (malocclusion, removal of incisors) or digestive diseases, from obesity, untreated infected wounds, or that are disabled (fracture of the spine, limb, arthritis, spondylosis). Indeed, the inability to groom the perianal and tail regions, or eat their cecotropes feces can lead to the appearance of a smell that will inevitably attract flies.

www.city.nagoya.jp/10eisei/ngyeiken/insect/d_callip/ls.htm

Left to Right: Lucilia sericata fly, larvae and pupa.

Myiasis flies lay eggs in the skin soiled with feces or diarrhea, on skin irritated by urine or in untreated infected wounds. The larvae that emerge from the hatched eggs will immediately start burrowing themselves through the skin, into the flesh of the host animal. A consequence is septicemia and shock, which lead to the rapid death of the rabbit.

Kerry Su-Lin Leow

Rescued rabbit with bite wound heavily infected by fly maggots. In spite good medical care and signs of recovery, the rabbit died. The use of prophylactic solutions is not recommended as adverse fatal effects have been observed in rabbits (Frontline). Some veterinary professionals use the prophylactic product Dicyclanil (Novartis), which protects sheep against the blowfly Lucilia sp. The product is not registered for use in rabbits, and a safe use in rabbits can thus not be guaranteed.

Clinical signs

The early stages of myiasis are often subclinical. With time, a rabbit becomes depressed, weak, loses weight and shows paresis. At this stage, the infection becomes visible; the larvae are about 1 cm long and their hind part protruding from the respiratory hole (spiracle) in the skin. In a severe case, alopecia is observed. The skin is inflamed, injured with signs of necrosis, and is often accompanied by the smell of ammonia. The later is excreted by the larvae, in order to cause cell death and decomposition, will cause an intoxication of the rabbit. Aberrant migration of the larvae is possible. Migration into the trachea has been observed. This leads to the formation of a laryngeal edema, blocking the air supply to the lungs. It may be accompanied by concurrent accumulation of mucus and swelling of the esophagus.

MediRabbit

Paralyzed rabbit and contamination of the skin by feces (arrows).

Diagnosis
The history of the rabbit and the clinical signs are generally sufficient for a proper diagnosis.

MediRabbit

Paralysis or severe arthritis can lead to incontinence and skin soiled with urine and cecotropes.

MediRabbit

The smell of urine soiled skin and soft cecotropes will attract Lucilia sp. female flies. These will lay eggs on the damaged skin.

Treatment
The hair is delicately clipped away around the infected area and each larva is removed individually and entirely with the aid of forceps, without crushing it, to prevent skin irritation or the development of an allergic reaction. The wounds are cleaned with a sterile saline solution, an antiseptic solution (e.g. povidone-iodine or chlorhexiderme). There is no need to use an insecticidal solution, if all the maggots have been removed.

Video: Fly Strike In Rabbits (1): Symptoms and Treatment

Aberrant migration brings the larvae deep under the skin or in vital organs. Three options are available here:

• Injection of ivermectin (0.4 mg/kg, SC). The rabbit must be closely monitored as the dying larvae excrete a toxin that can be fatal to animals, including rabbits. Although controversial, corticosteroids are sometimes given to the affected animal, in order to reduce the swelling.

• Injection of doramectin (0.5 mg/kg, SC).

• Surgical removal, under anesthesia, in case of aberrant migration or infection by Cuterebra sp..

Use of antibiotics is indicated, if the myiasis infection is severe. They help fight a secondary bacterial infection of the wounds and prevent sepsis, which can be fatal in rabbits. The administration of non-steroidal pain medication is necessary (e.g. meloxicam, carprofen). When the affected rabbit has stopped to eat, it must be hand-fed and given SC fluid therapy, in order to avoid the onset of fatal hepatic lipidosis and dehydratation. Depending on the situation, the affected rabbit can furthermore be administered appetite stimulants, or gut motility medication (e.g. cisapride, metoclopramide).

Bathing the rabbit with antiseptic or insecticide solution is not indicated. This procedure is stressful for the rabbit, and often ends in a panic reaction as soon as the fur is wetted or death by heart-arrest. A jump out of the bathtub has led to broken limbs or fracture of the spinal cord. If this method is nevertheless chosen, the rabbit should be dried with a towel and a hair-dryer or placed under a heat lamp. The heat will indeed bring the remaining worms to the surface of the skin, from where they can be easily discarded.

If a rabbit is heavily affected by myiasis, euthanasia should be considered. Prevention of myiasis can be done by addressing the causes of fecal or urine contamination of the skin, and by keeping the rabbit in a clean hygienic environment. Daily inspection of the perianal region is necessary in rabbits prone to suffer from digestive disorders, that are obese or that are disabled. The fur should be combed with a flea-comb, in order to detect the eventual presence of eggs and/or maggots. The windows of the apartment or the cage of the rabbit can furthermore be covered with a mosquito net, in order to avoid the insects to have contact with the rabbit.

Video: Fly Strike In Rabbits (2): Prevention

For detailed information on fly strike infestation in rabbits,

see: “Skin Diseases of Rabbits”

by E. van Praag, A. Maurer and T. Saarony,

Acknowledgement
Many thanks to Kerry Su-Lin Leow (Singapore) for sharing her pictures.

Further Readings
Baird CR. Biology of Cuterebra lepusculi Townsend (Diptera: Cuterebridae) in cottontail rabbits in Idaho. J Wildl Dis. 1983;19(3):214-218.

Harcourt-Brown F.: Textbook of Rabbit Medicine. 1st ed., Butterworth-Heinemann, Oxford, England, 2002.

Hess L. Dermatologic diseases. In: Ferrets Rabbits and Rodents. Clinical Medicine and Surgery, 2nd ed., (Quesenberry K.F., Carpenter J.W.) Saunders, St-Louis, USA., 2004.

Jacobson HA, McGinnes BS, Catts EP. Bot fly myiasis of the cottontail rabbit, Sylvilagus floridanus mallurus in Virginia with some biology of the parasite, Cuterebra buccata. J Wildl Dis. 1978;14(1):56-66.

Newell GB. Dermal myiasis caused by the rabbit botfly (Cuterebra sp). Arch Dermatol. 1979;115(1):101.

Schumann H, Schuster R, Lange J. The warble fly Oestromyia leporina (Diptera, Hypodermatidae) as a parasite of the wild rabbit (Oryctolagus cuniculus). Angew Parasitol. 1985;26(1):51-52.

Weisbroth SH, Wang R, Sacher S. Cuterebra buccata: immune response in myiasis of domestic rabbits. Exp Parasitol. 1973; 34(1):22-31.

e-mail: info@medirabbit.com


Dernière édition par végétalienne-13 le Mar 28 Mai - 14:41, édité 1 fois
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MessageSujet: Re: english myiasis = flies , worms into animals    Dim 19 Mai - 16:15

february the 20th of 2009








Myiasis (botfly) in rabbits



Esther van Praag Ph.D.





Warning: this file contains pictures and videos that may be distressing for people.



Myiasis caused by larvae of the Cuterebra sp. flies is found only in the USA. It is most commonly observed during the hot humid summer months and during fall, and affects mainly younger animals. Cuterebra sp. flies are large, hairy, and characterized by the absence of a functional mouth. Their life span is short, and aimed only at the reproduction of the species. The larvae of several species of the Cuterebra sp. flies can infest rabbits and other lagomorphs. They include Cuterebra buccata, C. cuniculi, C. lepivora, C. abdominalis, C. jelloni, C. ruficrus, and C. lepusculi. The parasitic larvae of these flies can infest human beings and other animals as well, including dogs, foxes, cats, and minks.
Unlike with fly-strike, a Cuterebra sp. larva strike is not linked to poor hygiene. Indeed, the eggs are not deposited on skin soiled with urine or excrement, but near the entrance to a rabbit burrow, other lagomorph nests, or near an outdoor rabbit hutch. House rabbits can also be struck by botfly larvae, when a fly enters a home, and deposits eggs in the rabbit's living environment. When the botfly larva emerges from the egg, it will migrate onto a (wild) rabbit, cottontail, or hare. It enters the body of its host through the skin (breaks in the skin or any natural openings), after which it penetrates the mucosa. The larva will migrate further in the body, using the trachea and the abdominal cavity to move to a subcutaneous location. There it will develop a 2 to 3 cm long furunculoid cystic structure, with a fistula (respiratory hole) at the surface of the skin, and swelling of the subcutaneous tissues.


cedarcreek.umn.edu/insects/newslides/029102002001apl.jpg



Botfly Cuterebra sp. and maggot


Depending on the species of botfly, the cysts will develop in different parts of the rabbit's body. Larvae of C. buccata can infest the entire abdominal region (especially the inguinal area, abdomen or shoulders), whereas larvae of C. horripilum have mainly been observed in the cervical region. When the larva reaches the stage of pupation, it disengages from the cyst and falls off.


Connie Andrews
Neck of a rabbit infested with a Cuterebra sp. larva

Connie Andrews www.bright.net/~bryanvet/Cuterebra.htm

Left: Close view of the respiratory hole
Right: Larva after surgical removal



Clinical signs
The clinical signs are generally sufficient for a proper diagnosis.
The early stages of myiasis are sub-clinical. With time however, a rabbit becomes depressed, anorectic, dehydrated and weak, loses weight, and may go into shock if the infection is severe. At this stage the infection becomes discernible, with a visible fistula in the skin, accompanied by a lump or a cystic structure. The lesion is painful, and causes great distress to the rabbit.
Progressively the skin around the hole becomes moist, and the surrounding hair matted, leading to the development of secondary bacterial or fungal infections.
There is potential for aberrant migration of the larvae into the nasal cavity and sinuses, or the eyes. Migration into the trachea has also been observed, leading to the formation of laryngeal edema, blocking the air supply to the lungs, and sometimes accompanied by concurrent accumulation of mucus, and swelling of the esophagus. Migration into the brain, via the ear canal is a further potential danger. Once in the brain, it will cause severe and irreversible neurological damage.
Diagnosis
The history of the rabbit and the clinical signs are generally sufficient for a proper diagnosis.


Joanne Vujnovich

Cottontail affected by a Cuterebra sp. maggot in the neck, and detail of the hole.




Treatment
The skin is prepared as for a surgical procedure, with the hair delicately clipped around the infected area, and the skin disinfected with an antiseptic solution. After enlargement of the breathing hole, the larva is carefully removed with the aid of forceps, without damaging or crushing it, in order to prevent skin irritation, and especially in order to prevent the occurrence of a (fatal) anaphylactic reaction. After removal of the larvae the cavity is cleaned with a sterile saline solution, an antiseptic solution, and an insecticide solution.

If necrotic tissue is present, the cavity should be carefully debrided. If an abscess has formed in the cavity, surgical excision of the tissues is necessary, followed by topical and systemic antibiotic therapy.

Aberrant migrated larvae, located deep under the skin or in vital organs, are removed surgically, under anesthesia.

The administration of non-steroidal analgesics (pain medication) is necessary (e.g. meloxicam, carprofen) after the procedure. If the affected rabbit stops eating, it should be hand-fed, in order to avoid fatal hepatic lipidosis.

If a rabbit is heavily infested with botfly larvae, euthanasia should be considered.



For detailed information on botfly infestation in rabbits,

see: “Skin Diseases of Rabbits”

by E. van Praag, A. Maurer and T. Saarony,

408 pages, 2010.





Acknowledgement
Thanks are due to Connie Andrews, to Joanne Vujnovich, and the owner of “Cedar Creek Natural History Area” for the permission to use their illustrative material. Thanks also to Tal Saarony, for her critical reading of the text.

Further Readings
Baird CR. Biology of Cuterebra lepusculi Townsend (Diptera: Cuterebridae) in cottontail rabbits in Idaho. J Wildl Dis. 1983 Jul;19(3):214-8.

Jacobson HA, McGinnes BS, Catts EP. Bot fly myiasis of the cottontail rabbit, Sylvilagus floridanus mallurus in Virginia with some biology of the parasite, Cuterebra buccata. J Wildl Dis. 1978 Jan;14(1):56-66.

Schumann H, Schuster R, Lange J. The warble fly Oestromyia leporina (Diptera, Hypodermatidae) as a parasite of the wild rabbit (Oryctolagus cuniculus). Angew Parasitol. 1985 Mar;26(1):51-52.

Weisbroth SH, Wang R, Sacher S. Cuterebra buccata: immune response in myiasis of domestic rabbits. Exp Parasitol. 1973 Aug;34(1):22-31.












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MessageSujet: Re: english myiasis = flies , worms into animals    Mer 22 Mai - 11:34

14 may 2010

Common green bottle flyFrom Wikipedia, the free encyclopediaJump to: navigation, search Common green bottle fly

Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Calliphoridae
Genus: Lucilia
Species: L. sericata
Binomial name
Lucilia sericata
(Meigen, 1826)
Synonyms
Phaenicia sericata (Meigen, 1826)
Lucilia nobilis (Meigen, 1826)[1]
Musca nobilis Meigen, 1826[1]
Musca sericata Meigen, 1826[1]


The common green bottle fly (Lucilia sericata) is a common blow-fly found in most areas of the world, and the most well-known of the numerous green bottle fly species. It is 10–14 mm long, slightly larger than a housefly, and has brilliant, metallic, blue-green or golden coloration with black markings. It has black bristle-like hair and three cross-grooves on the thorax. The wings are clear with light brown veins, and the legs and antennae are black. The maggots (larvae) of the fly are used for maggot therapy.

Contents [hide]
1 Distribution and behavior
2 Morphology
3 Life cycle
4 Forensic importance
5 Veterinary importance
6 Medical importance
7 Continuing research
8 References
9 External links


[edit] Distribution and behaviorL. sericata is common all over the world, mainly the southern hemisphere, dominating in Africa and Australia. It is coastal in its distribution and prefers warm and moist climates.[2] The female will lay her eggs in meat, fish, animal corpses, infected wounds of humans or animals, and excrement. The larvae of this insect feed on most decomposing tissue, but seem to concentrate on the Ovis genus which cause many problems for sheep farmers. This insect is also typical to most fly species by having three instar stages, a pre-pupa stage, and a pupa stage.

[edit] MorphologyThe defining characteristic of L. sericata, and most used when identifying the adult fly is the presence of three bristles on the dorsal mesothorax. This body region is located on the middle of the back of the fly. L. sericata is almost identical to its sister species, Lucilia cuprina. Identification between these requires microscopic examination of two main distinguishing characteristics. As opposed to L. cuprina which has a metallic green femoral joint in the first pair of legs, L. sericata is blue-black. Also, when looking at the occipital setae, L. sericata has 6–8 bristles on each side while L. cuprina have only one. [3]

[edit] Life cycle
L. sericata begin their life cycle by laying a mass of eggs in a wounded area, a carcass or corpse, or in necrotic or decaying tissue. The eggs will hatch out in anywhere from 8–10 hours in warm moist weather to three days in cooler weather. L. sericata can have a lifetime reproductive output of 130 to 172 eggs The pale yellow or grayish conical larvae, like that of most blowflies, have two posterior spiracles through which respiration occurs.These larvae are moderately sized ranging from 10 to 14 millimeters long.

The larva feeds on the dead or necrotic tissue anywhere from 3 to 10 days, again, depending on the temperature. During these 4 to 8 days the larva passes through 3 larval instars. The larval instars will develop according to the temperature in their environment. The cooler the temperature (16˚C) the first larva instar will take about 53 hours, the second instar will take about 42 hours and the third instar will take about 98 hours to complete that portion of their life cycle. At warmer temperatures (27˚C) the first larva instar will take about 31 hours, the second instar will take about 12 hours, and the third instar will take about 40 hours to complete that specific stage of the life cycle. [4] The third instar larva will then drop off of the host onto soil where it will pupate for 6 to 14 days. However, if the temperature is relatively cold, the pupa can also overwinter in the soil until the soil temperature warms again. After the pupa transforms, the adult will emerge from the soil and also feed on dead or necrotic tissue. Adults usually lay eggs about 2 weeks after they emerge. Their total life cycle ranges from 2 to 3 weeks, but again can be shortened during the summer when they are most active, or lengthened in cooler seasons. L. sericata usually completes 3 or 4 generations each year.[5]

[edit] Forensic importanceL. sericata is an important species to forensic entomologists. Like most Calliphorids, the insect has been heavily studied and its life cycle and habits are well documented. Due to this, the stage of the insect’s development on a corpse is used to calculate a minimum period of colonization, so that it can used to aid in determining the time of death of the victim. The presence or absence of L. sericata can show a lot about the conditions of the corpse. If the insects seem to be on the path of their normal development, it is likely that the corpse has been undisturbed. If however, the insect shows signs of a disturbed life cycle, or if it is absent from a decaying body, this can show signs of post-mortem tampering with the body. Because L. sericata is one of the first insects to colonize a corpse, it is preferred over many other species in determining an approximate time of colonization. Developmental progress is determined with relative accuracy by measuring the length and weight of larval life cycles.[6]

[edit] Veterinary importanceMany blowflies have an impact in the veterinary sense, and L. sericata is no exception. In places like the UK and Australia L. sericata is commonly referred to as the "sheep blowfly" since sheep are its primary host. Although it affects mainly sheep, L. sericata is not host-specific.

In northern Europe, the fly will lay its eggs in sheep wool. The larvae will then migrate down the wool where it will feed directly on the skin surface. This can cause massive lesions and secondary bacterial infections. In the UK, it is estimated that blowfly strike affects 1 million sheep as well as 80% of sheep farms each year. This causes a huge economic impact in these regions. Not only does it cost money to treat infected animals, but also, measures must be taken to control L. sericata.

Since this fly tends to lay its eggs in wool, a simple and effective way to reduce the incidence of infection is to shear ewes regularly. Enacting simple sanitary measures can also reduce blowfly strike. Timely and proper disposal of carcasses and proper removal of feces can aid in significantly reducing strike. Moving sheep from warm, humid, and sheltered areas to more open areas can also help to reduce blowfly strike, for this eliminates conditions conducive to fly development. Trapping systems such as sticky paper may also be used to control fly numbers. Treating a flock with chemical agents can be costly but can aid greatly in maintaining the resistance of the flock to L. sericata. Plunge dipping in diazinon can directly kill the fly on contact. This method works from 3 to 8 weeks in controlling the fly. An alternate chemical method is a pyrethroid pour-on, which will last from 6 to 10 weeks depending on the exact type of pyrethroid used. Cryomazine and dicylanil, which are insect growth regulators, are also effective and last from 10 to 16 weeks. Although chemical treatment can be very effective, it is costly, tedious, and takes up valuable time. [7]

[edit] Medical importanceL. sericata has been of medical importance since 1826, when Meigen removed larvae from the eyes and facial cavities of a human patient. L. sericata has shown promise in three separate clinical approaches. First, larvae have been shown to debride wounds with extremely low probability of myiasis upon clinical application. Larval secretions have been shown to help in tissue regeneration. L. sericata have also been shown to lower bacteremia levels in patients infected with MRSA. Basically, L. sericata larvae can be used as biosurgery agents in cases where antibiotics and surgery are impractical.

Studies have shown that larval secretions in vitro have been successful in enhancing fibroblast migration to wound site, positively impacting wound closure. [8] It is found that larval therapy of L. sericata is highly recommended for the treatment of wounds infected with Gram-positive bacteria, yet is not as effective for wounds that are infected with Gram-negative bacteria. Also, studies shown that bacteria from the genus Vagococcus were resistant to the maggot excreta/secreta. [9] Attempts are currently undergoing to extract or synthesize the chymotrypsins found in larval secretions to destroy MRSA without application of the larva itself.[10]

[edit] Continuing researchDue to this species' high forensic interest, extensive research on its life cycle has already been conducted. Medically, however, research is ongoing centered on the secretions produced by L. sericata as an agent against MRSA and VRSA[11] , and the larval applications for maggot therapy. Efforts in the latter are geared toward making medical professionals more familiar to the current techniques. [12] Like many other ectoparasites, L. sericata has a huge economic impact on farmers. Due to this, many studies and research projects have been put in place since the late 1980’s to help farmers reduce the impact of L. sericata.

[edit] References1.^ a b c Chandler, Peter J. (1998). "Checklists of Insects of the British Isles (New Series) Part 1: Diptera". Handbooks for the Identification of British Insects. 2 (London: Royal Entomological Society of London) 12 (1): 1–234.
2.^ [1] Australian Museum: Decompostition: Corpse fauna page
3.^ Bishop, Dallas. Variations in numbers of occipital setae for two species of Lucilia (Diptera: Calliphoridae) in New Zealand. New Zealand Entomologist. 1991. Vol 14. 29-31. [2]
4.^ [3] Australian Museum: Development times of Lucilia sericata at different temperatures: Corpse fauna page
5.^ Cetinkaya, Merih et al. Turkish Journal of Pediatrics."Neonatal myiasis: a case report. 50.581-584. 2008.
6.^ *Tarone AM, Foran DR. U.S. National Library of Medicine. Pub-Med. Generalized additive models and Lucilia sericata growth: assessing confidence intervals and error rates in forensic entomology. July 2008.
7.^ Sargison, Neil. “The Management of Ectoparasitic Diseases of UK Sheep”. World Veterinary Congress. Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Center, Roslin, Midlothian, Scotland. 27-31 July 2008.
8.^ Horobin et al. Maggots & Wound healing: The Effects of Lucilia sericata Larval Secretions upon Human Dermal Fibroblasts. European Cells and Materials. Vol. 6 Suppl 2, 2003 (3)
9.^ Jaklic, Domen. Journal of Medical Microbiology. “Selective antimicrobial activity of maggots against pathogenic bacteria”. 57. 617-625. (2008)
10.^ [4] Chymotrypsin From Lucilia sericata Larvae and its Use for the Treatment of Wounds
11.^ Cazander, G et al. Journal of Tissue Viability."Do maggots have an ifluence on bacterial growth? A study on the susceptibility of strains of six different bacterial species to maggots of Lucilia sericata and their excretions/secretions 2009.
12.^ Jones, Gemma & Wall, Richard. Research in Veterinary Science. Maggot-therapy in veterinary medicine. 85. 394-398. 2008.
[edit] External links Wikimedia Commons has media related to: Lucilia sericata

[5] Closeup photographs of Lucilia sericata
Maggot Therapy Project web site at the University of California, Irvine, list of maggot therapy practitioners
Green Bottle Maggots help cure MRSA patients
Monaghan, Peter Rx:Maggots, Notes from Academe, The Chronicle of Higher Education, June 1, 2007 (Vol. LIII, No. 39), p. A48.
Lucilia sericata on the UF / IFAS Featured Creatures Web site
Retrieved from "http://en.wikipedia.org/w/index.php?title=Common_green_bottle_fly&oldid=490944546"
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MessageSujet: Re: english myiasis = flies , worms into animals    Mer 22 Mai - 12:13

august 10 , 2012

Myiasis (Maggots) in Dogs

By PetPlace Veterinarians

Myiasis is a the term used to describe a maggot infestation. Maggots are fly larva that feed on necrotic and dying tissue. Especially prone are those pets confined to the outdoors with situations in which their skin remains moist. This includes pets with draining wounds, urine or fecal stained hair coats, or bacterial skin infections. Sustained skin moisture can cause damage, inflammation and infection setting up a favorable environment for maggots. This applies especially to weak and debilitated pets.

The majority of maggots found on pets are larva from blowflies (family
Callliphoria). The blowfly lays many eggs on decaying, infected or inflamed tissue. In favorable weather (warm and moist) the eggs hatch within 24 hours. The cone shaped larva uses its specialized mouth parts, including hooks, to lap up liquids and pierce the skin. After feeding and maturing for 5-7 days, the maggots leave the animal and enter the soil. Adult flies then emerge a few weeks later. Some maggots only invade dead or dying tissue. Unfortunately, some do not know when to stop and leave the decaying tissue to start feeding on healthy tissue.

What to Watch For

•Moist skin areas, especially around wounds or where urine or feces touch skin

•Small thin tubular worms found in wounds that range in size from 1/4 inch to one inch, often approximately the size of a grain of rice. They are rarely found alone.

Diagnosis

Diagnosis of myiasis is based on visualizing the maggots on the skin or in the wounds. Fly eggs can sometimes be found. Eggs (also called fly blow) are small white and sticky. They usually can only be removed by shaving the hair. After diagnosing myiasis, the underlying infection or skin problem that led to the maggot infestation should also be investigated and treated.

Treatment

Treatment of myiasis is to remove the maggots physically. Maggots are quite hardy and can be difficult to kill safely. Many potent insecticides can kill maggots but they put the weak and debilitated pet in danger of insecticide poisoning. Shaving the hair from the affected area is the first step. After hair removal, the extent of the maggot infestation can now be seen. Frequently, the maggots hide under the hair coat and extend a lot further than initially suspected. After shaving, physically removing the maggots – sometimes one at a time – is the next step. Frequently, there are hundreds of tiny maggots that burrow under the skin, and removal of all maggots may take several hours.

Mild insecticide can be applied briefly and then washed off to reduce potential harm to the pet. After removal of the maggots, the skin must be allowed to heal. In severe cases, sections of skin die and must be removed. If a significant amount of skin has been damaged, skin grafts may be required.

Home Care and Prevention

If caught early, the skin can be shaved and the maggot removed. Frequently, the owners are unaware of the maggots due to the hair coat covering the area. Most maggot infestations should be examined and treated by a veterinarian. The best way to prevent myiasis is to prevent skin diseases or infections that attract blowflies. Wounds should be cleaned and treated promptly. Urine and feces should be thoroughly washed off daily. Weak and debilitated pets should remain primarily indoors and frequently checked for urine staining or fecal matter. Skin infections should be treated promptly.
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MessageSujet: Re: english myiasis = flies , worms into animals    Mer 22 Mai - 12:15

SCREWWORM MYIASIS

Myiasis is the infestation of live vertebrate animals with dipterous larvae, which for
at least a certain period feed on the host's dead or living tissue, liquid body
substances, or ingested food (27). Depending on their reliance on the host, such
larvae are classified as obligatory or facultative. Screwworms are classified as
obligatory because they feed on live tissue. Screwworm larvae penetrate deeply
into a wound of a warmblooded animal and feed on living tissue and body fluid.
Facultative larvae, which feed on dead tissue and decaying matter, may be
present in wounds — even simultaneously with screwworm larvae.
Etiology top
Screwworm myiasis is caused by two species of diptera larvae in the family
Calliphoridae, subfamily Chrysomyinae: Chrysomya bezziana (Villeneuve), Old
World Screwworm, and Cochliomyia hominivorax (Coquerel), New World
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Screwworm (15).
Host Range top
Any warmblooded animal, including human, is subject to screwworm myiasis, but
infestation in poultry or fowl is rare.
Geographic Distribution top
Screwworms survive from year to year in tropical and semitropical regions. The
insect is killed by freezing temperatures or long periods of near-freezing
temperatures. Because of susceptibility to low temperatures, occurrence of
screwworms may be seasonal, and rarely are they found more than 7,000 feet
above sea level.
New World Screwworm was first reported in the southeastern part of the United
States in 1933 and probably had been introduced through the importation of
animals with screwworm myiasis from the southwestern United States (3). New
World Screwworm survived winters in the United States in Florida and Texas and
occasionally in southern Arizona and California. During the spring and summer,
screwworms spread north to the central United States, creating a seasonal
problem for livestock and wildlife.
Eradication of the New World Screwworm from the southeastern United States was
initiated in early 1959. This effort was aided by a colder than normal winter that
limited survival of the insect to the southern half of the Florida peninsula. Near the
end of 1961, the southeastern United States was declared free of this pest. Then,
in early 1962, a similar eradication program was initiated in the southwestern
United States. Again the program was aided by a colder than normal winter that
limited survival of the insect to the southernmost part of Texas. Near the end of
1964, the screwworm was declared eradicated from all of the contiguous states of
the United States. From 1965 to 1981, a buffer zone was maintained, with varying
degrees of success, along the entire expanse of the United States-Mexican border
region. The objective of the buffer zone was to control the migration of the
screwworm from Mexico into the Untied States and to minimize the incidence of
cases of screwworm in the region.
In August 1972, an agreement between the United States and Mexico was signed
establishing a joint commission to eradicate screwworm from Mexico. Such an
action was considered necessary to prevent screwworm infestation in the United
States totally. Eradication of the screwworm from Mexico was initiated near the
end of 1976, and progressed from north to south (17). The last local case of
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SCREWWORM MYIASIS
screwworm in the United States was reported from Star County, Texas, in August
1982. Mexico and the United States signed agreements with Guatemala in 1986,
and Belize in 1988, to extend the joint eradication program into those countries.
Mexico was declared free of the screwworm in February 1991.
Cattle movements from Central America north into Mexico continued to present a
threat of reinfestation. Such activity was probably responsible for outbreaks
discovered in central and southern Mexico in 1992 and 1993. These outbreaks
were rapidly contained and eliminated.
The United States signed agreements with Honduras, El Salvador, and Nicaragua
in 1991, with Costa Rica in 1993; and with Panama in 1994. To maintain the North
American continent free of the screwworm, it was considered necessary to extend
the eradication program to Central America and Panama. A permanent barrier will
be established at the Isthmus of Panama to prevent reinfestation of regions to the
north.
Guatemala and Belize were declared free of the screwworm in 1993. Then El
Salvador and Honduras were declared free of the pest in 1995 and 1996,
respectively. The last local case of screwworm in Nicaragua was reported in
February 1997. Eradication of the screwworm was initiated in Costa Rica in early
1996 and is scheduled to be initiated in Panama in 1998.
Other regions of the Western Hemisphere that have been freed of the New World
Screwworm are Puerto Rico, the Virgin Islands, and the island of Curacao of the
Netherlands Antilles. New World Screwworm is present on several of the islands in
the Caribbean Sea and in the tropical and semitropical regions of South America.
There is a seasonal spread of the screwworm into the temperate regions of
Argentina, Uruguay, and Paraguay in the spring and summer (12). Rarely is
screwworm reported in Chile or southern Argentinia, and then only from imported
animals.
The only recorded establishment of New World Screwworm in the Eastern
Hemisphere was in a 20,000-square kilometer area around Tripoli, Libya, in north
Africa. Introduction of the screwworms is thought to have occurred with animals
imported from South America during or before 1988. The outbreak was eradicated
in 1991.
Old World Screwworm has never become established in Europe, North Africa, the
Middle East, Australia or the Western Hemisphere. It is found in most of the
remainder of the tropical and semitropical regions of the Eastern Hemisphere: the
Indian subcontinent, Southeast Asia, the main island of Papua New Guinea,
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SCREWWORM MYIASIS
tropical and sub-Saharan Africa , Oman, Muscat, Fujaira, and Kuwait (24).
Life Cycle top
Screwworm larvae feeding in a wound are closely packed. As the larvae feed, they
destroy tissue, thus continually making the wound larger. Within 5 to 7 days the
larvae reach maturity. At this stage of development (third instar), the larvae will
exit the wound and drop to the ground. Mature larvae are negatively phototrophic
(i.e., they move away from light and usually burrow 2 to 5 cm deep in the soil,
where they develop into pupae. Many larvae do not survive owing to desiccation
and predation (2). Transformation into the fly occurs during the pupal stage and
may take about 7 days at 28° C (82.4° F) or may take as long as 60 days at
temperatures of 10-15° C (13,21).
Flies that survive during this stage of development emerge from the pupal casing,
taking about 2 hours to dry, spread their wings and then seek food such as water
and nectar. Survival of the flies is dependent on temperatures, humidity, food
sources, host availability, and other ecological factors (21). Ambient air
temperatures of 25-30° C (77-86° F) with a relative humidity of 30-70 percent are
ideal parameters for screwworm fly activity and survival. Adult screwworm flies
find superficial wounds on warmblooded animals and feed on fluids in the wound.
After 3-5 days the flies are ready to mate. Male screwworm flies will mate several
times. Females usually mate once. About 3-4 days after mating, the female fly
seeks a superficial wound on a warmblooded animal to oviposit eggs along the
edge of the wound in a shinglelike manner. Larvae up to 2 mm in length emerge
from the eggs in 8 to 12 hours, enter the wound, and begin feeding.
Female New World Screwworm flies oviposit up to 400 eggs in a single egg mass
and one fly may oviposit 6 to 8 batches of eggs in her life (25). An egg mass from
the Old World Screwworm contains about 100 to 250 eggs (15). Male screwworm
flies usually survive about 14 days; females often survive 30 days.
Transmission top
The distance that female screwworm flies travel depends on the ecological
conditions, food supply, and availability of hosts with suitable wounds. The female
flies tend to range only 10-20 km in tropical environments when there is a high
density of animals. In arid environments with lower densities of animals,
screwworm flies have traveled as far as 300 km (12). Often in more arid areas,
screwworm flies will travel along water courses. In mountainous areas, screwworm
flies will travel the course of valleys, where the climate is warmer, moisture is
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SCREWWORM MYIASIS
high, and animal density is high. Vehicles, especially those transporting animals,
may contribute to dispersing screwworm flies in some areas. Wind may also be a
factor.
Transmission of screwworms into nonendemic areas and over long distances is
often the result of transporting animals with screwworm myiasis or carrying
screwworm adults on transport vehicles. When new infestations are not treated
and larvae mature and exit the wounds, there is the potential for screwworms to
become established in a new area.
Clinical Signs top
Wounds that may become infested by screwworms include those caused by
engorged ticks, bites of vampire bats, castration, dehorning, branding, wire cuts,
sore mouth in sheep, shedding of the velvet in deer, and a multitude of other
causes. Navels of newborn mammals are a common site for screwworm
infestation. Early stages of the larvae feeding in a wound are very difficult to see;
only slight movement may be observed. As the larvae feed, the wound is gradually
enlarged, becoming wider and deeper. By the third day, as many as 100 to 200
tightly packed, vertically oriented larvae can easily be observed embedded deep in
the wound. Screwworm larvae tend to burrow deeper in a wound when disturbed
and will generally not be seen crawling on the surface (Fig. 100).
After 5 to 7 days, a wound may be expanded to 3 cm or more in diameter and 5
to 20 cm deep with larvae from a single screwworm egg mass. Usually by this
stage, additional screwworm flies have deposited eggs, resulting in a multiple
infestation. A serosanguineous discharge often exudes from the infested wounds,
and a distinct odor may be detected. In some cases, the openings in the skin may
be small with extensive pockets of screwworm larvae beneath. In dogs,
screwworm larvae commonly tunnel under the skin. Screwworm infestations in
anal, vaginal, and nasal orifices may be difficult to detect, even in the later stages.
Animals with screwworm infestation usually display discomfort, may go off feed,
and produce less milk. Typically animals with screwworm myiasis will separate
themselves from the rest of the flock or herd and seek dark or shady areas to lie
down. Goats frequently hide in caves. Fawns have often been observed standing in
streams with water up to the abdomen when they have screwworm myiasis in the
navel. Brahman-type cows will often lick the screwworm-infested navel wounds of
calves — a process that cleans most larvae from the wound and reduces losses in
this breed of cattle. Animals with screwworm myiasis may die in 7 to 14 days if
wounds are not treated to kill the larvae — especially in cases of multiple
infestation. As many as 3,000 larvae may be found in a single wound (17). Death
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SCREWWORM MYIASIS
probably results from toxicity, a secondary infections, or both. Smaller animals
usually die of screwworm myiasis in a shorter time than larger animals. Location
of the wound infestation is also a determining factor in the time of death.
Morbidity and Mortality top
In some areas of the Western Hemisphere where screwworm populations are high
and climatic and ecological conditions are ideal, livestock owners report that every
newborn animal will get a screwworm infestation in the navel wound if it is not
treated soon after birth. A study on the King Ranch in south Texas in the United
States during the 1950's showed that screwworm seriously affected the deer
population. In some years, up to 80 percent of the fawns died due to screwworm
whereas in other years the death rate was around 20 percent (9). Mature larvae
exiting untreated wounds may contribute to increasing the screwworm fly
population in the immediate area, and, as the screwworm population increases,
the percentage of animals with superficial wounds that become infested also
increases.
Screwworm infestations that are treated and those that result from one oviposition
are usually not lethal to the animal; however, death is always a possibility,
especially in very small animals. Secondary infection is also common.
Animals with untreated screwworm infestations will often have more than one
screwworm fly oviposit at the wound site, or the same fly may oviposit more than
once. Left untreated, these multiple infestations often result in death of the
animal, within 7 to 10 days, depending on the size and condition of the animal,
the location of the infestation, and whether there are other complications such as
infection or toxicity. Animal deaths due to the Old World Screwworm appear to be
less common than with the New World Screwworm.
Diagnosis top
Field Diagnosis top
Screwworm myiasis should be suspected when the described clinical
manifestations are seen. New World screwworm may be observed as creamy white
eggs deposited in shinglelike fashion on the border of a superficial wound. Small
screwworm larvae up to 2 mm in length hatch from the eggs in 8 to 12 hours. Egg
masses of Old World Screwworm are indistinguishable except individual eggs are
larger. Eggs in the masses deposited by other species of blow flies are not well
organized. C. macellaria deposit eggs on the margin or in the hair close to a
wound. Microscopic examination is required to distinguish individual eggs of this
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SCREWWORM MYIASIS
species from those of the screwworm. Sarcophagidae species. deposit live larvae
into a wound or in soiled wool or hair. Larvae of these species are facultative and
may be seen in wounds, usually near the surface, feeding on necrotic tissue or
organic matter.
Larvae can be removed from a wound with tweezers. Second and third instar
screwworm larvae are cylindrical, are pointed at one end and blunt at the other,
and have complete rings of dark brown spines circling the body. The shape and
characteristics of the second or third instar larvae (Fig. 101) resemble a wood
screw, thus giving rise to the common name of the pest. Field diagnosis is difficult
— even for trained individuals. A magnifying glass or microscope is usually
necessary to see the distinguishing characteristics of the various insect stages. A
diagnosis in the field should always be considered presumptive.
Female screwworm flies may be observed visiting a wound. They are about two
and a half times the size of the common house fly. New World screwworm flies
have a darkblue to blue-green thorax with a reddish-orange head and have three
longitudinal dark stripes on the back of the thorax with an incomplete center stripe
(Fig. 102). Old World Screwworm flies have bodies that are green to bluish-black
and have two transverse stripes on the thorax. C. macellaria flies are similar but
have a green thorax with three complete dorsal stripes.
Specimens for the Laboratory top
Before treatment, a sample of larvae should be removed from the wound using
tweezers for submission to the laboratory. Eggs should be carefully removed from
the edge of the wound using a scalpel. For laboratory diagnosis, specimens of
eggs, larvae, or flies should be placed in 70 percent alcohol and sent to a
recognized diagnostic laboratory (do not use formalin as a preservative). Because
screwworm larvae penetrate deep into a wound, and other facultative larvae may
exist more superficially in the same wound, specimens of larvae for laboratory
diagnosis should be collected from the deepest part of the wound. In the United
States, send specimens to the National Veterinary Services Laboratories, P.O. Box
844, Ames, IA, 50010. Experienced professional personnel will identify the
specimens.
Differential Diagnosis top
Scewworm larvae must be differentiated from larvae of other species of blow flies
that may be present in a wound on any warmblooded animal.
Treatment top
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SCREWWORM MYIASIS
Before treatment, a sample of the larvae should be removed from the wound for
submission to a laboratory using tweezers. Screwworm myiasis is treated with
topical application of an approved larvacide directly into the infested wound.
Wounds should be retreated two to three times on successive days to ensure that
all of the larvae have been killed and removed. With this treatment, the wound
will heal rapidly and will not become reinfested with screwworm larvae
Vaccination top
There is no vaccine.
Control and Eradication top
Prevention
Where screwworm is endemic, animals must be inspected at least every 3 to 4
days to discover and treat cases of screwworm myiasis. Open wounds on animals
not infested with screwworm larvae should be treated to prevent infestation. In
areas where screwworm myiasis is a seasonal occurrence, animal breeding can be
regulated so births occur during the season when screwworm myiasis is rarely
encountered. Similarly, management practices that create wounds, such as
branding, castrating, dehorning, docking, or other operations, can be programmed
for the season when screwworm myiasis is rare.
Treating wounds and spraying or dipping animals with an approved
organophosphate insecticide will provide protection against screwworm infestation
for 7 to 10 days. Should a screwworm egg mass be deposited on the edge of a
wound on an animal treated with this insecticide, the newly hatched larvae will
encounter the residual insecticide as they crawl into the wound and will be killed.
This usually gives wounds sufficient time to heal. If wounds are already infested
with screwworm second-or-third instar larvae when an animal is sprayed or dipped
with the organophosphate insecticide, the treatment usually does not kill all larvae
present. Therefore, this form of treatment should be used only as a preventive
measure and not as a cure.
Preventing the introduction of screwworm into areas that have the ecological
environment for screwworm propagation but are currently without the pest is an
important aspect of control. Blocking such introductions is accomplished through
voluntary and regulatory actions. Immediately before being transported from
where screwworm is endemic, animals, this includes pets, should be thoroughly
inspected for the presence of a superficial wound subject to screwworm
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SCREWWORM MYIASIS
infestation. All wounds should be treated with an approved organophosphate
insecticide followed by a precautionary spraying or dipping of the animals before
they are moved. An animal having wounds suspected of being infected with
screwworm should not be moved until the wounds have been properly treated and
have healed.
Conveyances should be sprayed with insecticide to kill any adult or immature
screwworm flies. Upon arrival at the destination or port of entry, these animals
should again be inspected and undergo treatment of all wounds or suspected
screwworm myiasis.
Eradication
Eradication of the screwworm has been successful only when the sterile-male
technique has been applied to an area. After the lab-reared insects are in the
pupal stage for about 5.5 days, or 24 hours before the adult flies emerge, they are
exposed to 5,000 to 7,000 rads of gamma radiation. This exposure to radiation
renders the insects sexually sterile without adversely affecting them in any other
way (4). Once released, sexually sterile male screwworm flies mate with native
females. These females then deposit unfertilized eggs that, of course, do not
hatch, thus breaking the life cycle.
Eradication areas are blanketed weekly with an equal proportion of sterile male
and sterile female flies at the usual dosage rate of 3,000 per square mile. There is
currently no practical method of separating the mass-produced, lab-reared males
and females. Although eradication of the screwworm from an area may be
enhanced by releasing a higher proportion of sterile males, the benefit of releasing
sterile females needs further investigation. Nonetheless, use of the current
technology has been successful. The actual dosage of sterile screwworm flies
released over an area will vary according to the estimated local screwworm
population, host density, and the local ecology The dosage should be sufficient to
release 300 sterile male screwworm flies or more for one native male screwworm
fly (14). Using this technology together with larvacide treatment of wounds and
control of transport of screwworms through animal movements usually results in
eradication of the insect from that area in 2 years or less. This dosage of sterile
males will usually outnumber the native male screwworm fly population by 300 or
more to 1 (16).

Humans are susceptible to screwworm myiasis.
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SCREWWORM MYIASIS

sc. Publ. of the Entomological Society of America, No. 62.
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Date d'inscription : 17/05/2007

MessageSujet: Re: english myiasis = flies , worms into animals    Mar 18 Juin - 11:09

Hello everyone . Please everyone who receives this : Send this to all the people you know in order to save as many animals angels lives as posible . Thank you for them 

my English sucks . almost all the pets except fish can have myasis. its very disusting and dangerous for humans . it happens from may tos eptember of every year . it happens to old and sick animals and also to healthy and young ones. The flies put their eggs on animals who are very dirty or smell very bad or are full on pee and poo or on any animal who ate dog or cat poo with flies eggs in it or if they ate dog or cat food with flies eggs in it . one has to not let dog or cat foo in the garden because from may to september the flies put their egs inside and one mustnt let pet food outside, its best to give them the food inside because if they dont eat all of it , the flies put their eggs and later the pet eat it so the eggs are inside their boides and in a few hours they transformed in maggots and they kill the pet very fast in a few days if the parents of the pet dont do nothing immediately. they eat the poor animals very fast . the maggots are very well hidden under the fur so its very hard to see them. In fact, the pet can be for days with them and the parents don't even know it . So they can be dangerous for the other pets who ain't got myasis coz they are in contact with the ones who ot this disease . Humans can have myiasis too . So the parent, as soon as they know that their pet has maggots, must very quickly brin them to the vet coz if they don't do nothin the poor animals dies and sufferin a lot and beon eaten alive which causes a lot of pain , terrible suffering to the animal angel
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MessageSujet: Re: english myiasis = flies , worms into animals    Aujourd'hui à 19:55

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