Diseases / List of Parasitic Diseases / Disease description:

Feather Lice Infection in Waterfowl and Cranes

INFORMATION AVAILABLE

GENERAL INFORMATION

CLINICAL CHARACTERISTICS & PATHOLOGY

INVESTIGATION & DIAGNOSIS

TREATMENT & CONTROL

SUSCEPTIBILITY & TRANSMISSION

ENVIRONMENT & GEOGRAPHY

 

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General and References

Disease Summary

  •  Lice on feathers. Usually present in low numbers with minimal effect, but may become numerous in debilitated birds.

N.B. The shaft louse Holomenopon leucoxanthom causes wet-feather (Wet Feather) in waterfowl (B10.26.w11).

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Alternative Names (Synonyms)

  • Chewing Lice Infection
  • Mallophaga Infection

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Disease Type

 Parasitic - Insects, Mites and Ticks 

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Infectious/Non-Infectious Agent associated with the Disease

Feather lice, Mallophaga; both Amblycera and Ischnocera. Species of lice tend to be host-specific. Each waterfowl species may have its own species (B9.6.w1, B24, B48.19.w19, B198.8.w8a).
  • Feather lice are small (one to 10 mm, depending on species (B48.19.w19, B114)), have a dorso-ventrally flattened body, a relatively large, broad head, sometimes with a pair of rudimentary eyes, short antennae, robust mandibles, short legs with hooks on the ends, and no wings. (B48.19.w19, B114, B198.8.w8a)
  • Life cycle: Normally the whole life cycle takes place on the host. Eggs of species living on the wings are laid onto the feathers in rows on the flight feathers, normally in areas relatively safe from the host's bill (e.g. along the grooves between the barbs of the flight feathers). Other species lay their eggs singly or in clusters near the feather bases on the bird's head and neck. In birds which are heavily infested, eggs may be found on feathers all over the body Eggs hatch after about 3-5 days (longer if kept at lower temperatures); nymphs grow and develop through three instars, with about a week at each stage, adult lice emerging after about four weeks; the total life cycle takes about 30-36 days. (B48.19.w19, B114, B198.8.w8a)
  • Ischnocera (suborder) lice generally feed on feathers only, and are found in sharply defined areas, while Amblyocera (suborder) lice also take blood and serum, and may puncture the quill to take blood from the pulp of growing feathers. (B48.19.w19)
  • The lice can survive away from the host for only a few days. (B198.8.w8a)
  • The genus Gruimenopon is typically found parasitic on cranes (Gruidae). Gruimenopon canadensum measured 1.94 mm (14 males) and 2.29 mm (12 females). They were light tan in colour, with large, dark ocular and cervical sclerotizations and only slight sexual dimorphism except for the size difference. (J446.56.w1)

Infective "Taxa"

Non-infective agents

--

Physical agents

-- Indirect / Secondary

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References

Disease Author

Debra Bourne MA VetMB PhD MRCVS (V.w5)
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Major References / Reviews

Code and Title List

B24, B48.19.w19, B114, B198.8.w8a

Waterfowl
B9
.6.w1, B10.26.w11, B13.46.w1, B18, B24, B37.x.w1, 
J1.21.w4
J43.64.w1
P4.1992.w1

Cranes
J1.32.w10, J11.61.w2, J381.41.w1, J441.72.w1, J446.56.w1
P87.1.w3, P87.1988.w2, P92.1.w4, P99.1.w1
Th12

Other References

Code and Title List

J1.13.w6, J1.13.w7, J1.17.w6

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Clinical Characteristics and Pathology

Detailed Clinical and Pathological Characteristics

General

Often present without significant clinical effects except in young or ill birds. (B114)
WATERFOWL
  • Usually no clinical signs. Heavy infections may develop in debilitated birds and may then cause irritation and contribute to ill health.

N.B. Shaft louse Holomenopon leucoxanthom causes wet-feather (Wet Feather) (B10.26.w11).

CRANES --

Clinical Characteristics

  • With light infestations, usually none.
    • Quite heavy infestations may be present without apparent ill effect. (B114)
  • With severe infestations, irritation, which can be intense, leading to excessive preening and scratching; the bird can damage itself. General irritability.
  • The plumage may be dull and opaque, with feathers ruffled and damaged.
  • Feather shafts may become denuded and feather development may be inhibited by punctures in quills. Blood loss may occur from feeding lice.
  • Clinical pathology: slight anaemia, thrombocytosis and moderate leucocytosis may develop with prolonged heavy infestation (e.g. one month). (B48.19.w19)

(B48.19.w19, B114, B198.8.w8a)

WATERFOWL
  • Usually no clinical signs and present in only very low numbers. 
  • May become numerous in debilitated birds, particularly in birds which have stopped preening, and may then cause severe irritation, and further debility. 
  • Irritation due to heavy infestations may cause excessive preening.

(B10.26.w11, B13.46.w1, B18, B37.x.w1, B48.19.w19).

CRANES
  • Probably usually of little significance. (P87.1.w3, P92.1.w4)

Incubation

--
WATERFOWL --
CRANES --

Mortality / Morbidity

Heavy infestations can be severely debilitating. (B48.19.w19)
WATERFOWL Heavy infections in debilitated birds may contribute to illness and death (B18).
CRANES
  • May contribute to a crane's debilitating condition. (P92.1.w4)

Pathology

Plumage dull and damaged. Presence of adults and eggs on the feathers. (B198.8.w8a)
WATERFOWL --
CRANES
  • Probably usually of little significance. (P87.1.w3)

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Human Health Considerations

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Susceptibility / Transmission

General information on Susceptibility / Transmission

BIRDS Susceptibility
  • Infestation tends to be heavier in sick or injured individuals.
  • Preening by the bird probably limits louse infestations in healthy individuals.

Transmission

  • Direct contact, usually while the hosts are mating or brooding young, and at roosts of gregarious species.
  • Transfer may occur via dust baths.
  • Interspecific transfer is rare, except by lice searching for a new host after their host has died.

(B48.19.w19, B114, B198.8.w8a)

WATERFOWL Susceptibility
  • May be seen in all species; particularly common in swans.
  • Greater prevalence may be noted in juveniles than adults.
  • Louse numbers may increase dramatically on debilitated hosts.

Transmission

  • Direct contact.

(J1.21.w4, P4.1992.w1, B24, B37.x.w1, B48.19.w19)

CRANES Susceptibility
  • May contribute to a crane's debilitating condition. (P92.1.w4)

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Disease / Agent has been reported in either the wild or in captivity in:

Common on free-living birds as well as on cage and aviary birds (e.g. passerines, psittacines, raptors). (B198.8.w8a)

Presence of lice reported on waterfowl:

  • All swans except Coscoroba swan (B9.6.w1) (but see below).
  • Anaticola anseris and Anaticola crassicornis on ducks, Trinoton anserinum (= Trinoton anseris) on ducks and swans (B24).
  • Wild cinnamon teal Anas cyanoptera in southwest Texas, USA (J1.13.w6).
  • Wild northern shoveler Anas clypeata in southwest Texas, USA (J1.13.w7).
  • Wild green-winged teal Anas crecca in southwest Texas, USA (J1.17.w6).
  • 54% of wood ducks Aix sponsa in the Atlantic Flyway, USA (J1.21.w4).
  • Holomenopon goliath on magpie goose Anseranas semipalmata from Australia;
  • Holomenopon bohmi on Coscoroba swan Coscoroba coscoroba
  • Holomenopon leucoxanthum (see also: wet-feather (Wet Feather)) on plumed whistling-duck Dendrocygna eytoni, wandering whistling-duck Dendrocygna arcuata, Fulvous whistling-duck Dendrocygna bicolor, lesser whistling-duck Dendrocygna javanica, white-faced whistling-duck Dendrocygna viduata, greylag goose Anser anser, Canada goose Branta canadensis, radjah shelduck Tadorna radja, common shelduck Tadorna tadorna, mallard Anas plathyrhynchos, Pacific black duck Anas superciliosa, common (green-winged) teal Anas crecca, gadwall Anas strepera, American wigeon Anas americana, cinnamon teal Anas cyanoptera, northern shoveler Anas clypeata, red-creasted pochard Netta rufina, southern pochard Netta erythrophthalma, canvasback Aythya valisineria, common pochard Aythya ferina, redhead Aythya americana, hardhead Aythya australis, ring-necked duck Aythya collaris, tufted duck Aythya fuligula, lesser scaup Aythya affinis, greater scaup Aythya marila, comb duck Sarkidiornis melanotos, black scoter Melanitta nigra, long-tailed duck (oldsquaw) Clangula hyemalis, bufflehead Bucephala albeola, ruddy duck Oxyura jamaicensis;
    Holomenopon setigerum on common (green-winged) teal Anas crecca, gadwall Anas strepera, garganey Anas querquedula, blue-winged teal Anas discors, cinnamon teal Anas cyanoptera, Cape shoveler Anas smithii, northern shoveler Anas clypeata, maned duck Chenonetta jubata, white-winged duck Cairina scutulata;
  • Holomenopon acutae on northern pintail Anas acuta, cape teal Anas capensis; (J43.64.w1).
  • Holomenopon clauseni on blue-winged teal Anas discors, wood duck Aix sponsa; (J43.64.w1).
  • Holomenopon tumidum on spur-winged goose Plectropterus gambiensis; (J43.64.w1).
  • Holomenopon brevithoracium on black-necked swan Cygnus melanocoryphus, ruddy-headed goose Chloephaga rubidiceps, upland goose Chloephaga picta; (J43.64.w1).
  • Holomenopon bucephalae on common goldeneye Bucephala clangula and bufflehead Bucephala albeola, (J43.64.w1).
  • Holomenopon tadornae on brent goose Branta bernicla, Andean goose Chloephaga melanoptera, Egyptian goose Alopochen aegyptiacus, ruddy shelduck Tadorna ferruginea, common shelduck Tadorna tadorna; (J43.64.w1).
  • Holomenopon transvaalense on mallard Anas platyrhynchos; (J43.64.w1).
  • Holomenopon obscurum on radjah shelduck Tadorna radjah; (J43.64.w1).
  • Holomenopon cairinae on muscovy duck Cairina moschata; (J43.64.w1).
  • Holomenopon clypeilargum on American black duck Anas rubripes, yellow-billed duck Anas undulata, speckled teal Anas flavirostris, common (green-winged) teal Anas crecca, gadwall Anas strepera, Eurasian wigeon Anas penelope, American wigeon Anas americana, northern pintail Anas acuta, gargany Anas querquedula, blue-winged teal Anas discors, cinnamon teal Anas cyanoptera, northern shoveler Anas clypeata, canvasback Anas valisineria, ring-necked duck Aythya collaris, New Zealand scaup Aythya novaeseelandiae, greater scaup Aythya marila, hooded merganser Lophodytes (Mergus) cucullatus, common merganser Mergus merganser; (J43.64.w1).
  • Holomenopon loomisii on common eider Somateria mollissima, king eider Somateria spectabilis, white-winged scoter Melanitta fusca, red-breasted merganser Mergus serrator (J43.64.w1).

Presence of lice reported on cranes:

Host Species List

Waterfowl

Cranes:

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Disease / Agent has been specifically reported in Free-ranging populations of:

Common on free-living birds. (B198.8.w8a)

Presence of feather lice recorded on waterfowl:

  • Wild cinnamon teal Anas cyanoptera in southwest Texas, USA (J1.13.w6).
  • Wild northern shoveler Anas clypeata in southwest Texas, USA (J1.13.w7).
  • Wild green-winged teal Anas crecca in southwest Texas, USA (J1.17.w6).
  • Wild wood ducks Aix sponsa in the Atlantic Flyway, USA (J1.21.w4).

Presence of feather lice recorded on cranes:

WATERFOWL Host Species List

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Environment/Geography

General Information on Environmental Factors/Events and Seasonality

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Regions / Countries where the Infectious Agent or Disease has been recorded

"Practically cosmopolitan." (B198.8.w8a)
  • In waterfowl:
    • USA (J1.21.w4).
    • Australia, New Zealand, Austria, Taiwan, USA, Thailand, Canada, Switzerland, UK, Iceland, Colombia, Kenya, British Guyana, Sweden, South Africa, India, Uganda, East Africa, Israel, Transvaal, Paraguay, Falkland Islands, Congo, Sudan, Cameroon, Uganda, Ethiopia, Papua New Guinea, Brazil, Ecuador, Bolivia, Egypt, Kenya, Hungary, Lapland (J43.64.w1).
  • In cranes: USA, Europe. (J1.32.w10, J11.61.w2, J381.41.w1, J441.72.w1, P87.1.w3, P92.1.w4, P99.1.w1, Th12)

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Regions / Countries where the Infectious Agent or Disease has been recorded in Free-ranging populations

  • "Practically cosmopolitan." (B198.8.w8a)
  • In waterfowl: USA (J1.21.w4).
  • In cranes: USA, Europe. (J1.32.w10, J11.61.w2, J381.41.w1, J441.72.w1, P87.1.w3, P92.1.w4, P99.1.w1, Th12)

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General Investigation / Diagnosis

General Information on Investigation / Diagnosis

  • Presence of the adult and nymph lice on the feathers, and of eggs attached to the feathers.
  • Distinguished from other arthropods by their shape: dorso-ventrally flattened body and large broad head.
  • They can be collected by brushing the lice from the host onto a clean surface; large numbers can be collected by fluffing a safe, effective insecticide (e.g. pyrethrum dust) through the feathers, then leaving the bird in a box lined with a piece of paper; lice will crawl to the ends of the feathers and drop off, and can be collected and preserved in 70% alcohol. 

(B48.19.w19, B198.8.w8a)

WATERFOWL
  • Visual examination: black or brown cigar-shaped lice, 2-8mm long, moving around feather vanes, or eggs (B13.46.w1, B37.x.w1).
CRANES
  • Visual examination of the feathers. (J11.61.w2)
  • Ectoparasites can be collected using forceps or a fine-tipped brush, then killed, fixed and preserved in 70% ethanol prior to clearing and mounting for identification. (381.41.w1)
Related Techniques
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Similar Diseases (Differential Diagnosis)

  • Other small parasitic arthropods. (B198.8.w8a)
WATERFOWL Note: Further investigation is necessary with heavy infections, to find the underlying cause of debility (B37.x.w1).
CRANES [Other small parasitic arthropods.]

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Treatment and Control

Specific Medical Treatment

BIRDS
  • Pyrethrin-based insecticidal powders, or rotenone spray; repeat weekly to give a total of two or three treatments. (B198.8.w8a)
  • Nests can be treated with an appropriate insecticide. (B48.19.w19)
WATERFOWL
CRANES
Related Techniques
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General Nursing and Surgical Techniques

BIRDS Since few lice usually are found on healthy birds, keeping birds healthy controls louse infestations. (B48.19.w19)
WATERFOWL --
CRANES --
Related Techniques
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Preventative Measures

Vaccination BIRDS --
WATERFOWL --
CRANES --
Prophylactic Treatment

BIRDS

  • Maintaining healthy birds is the best method of controlling lice (B48.19.w19).
WATERFOWL --
CRANES
Related Techniques
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Environmental and Population Control Measures

General Environment Changes, Cleaning and Disinfection

BIRDS

  • Provide appropriate water and/or dust bathing opportunities: "bathing in water and dust and the subsequent preening helps the bird to rid itself of parasites." (B114)
WATERFOWL
  • Ensure sufficient water is always available for waterfowl to throw water over their backs while preening (B18).
CRANES
  • General good sanitation and management. Avoid stressors such as poor ventilation, sudden changes in temperature, excessive handling, excessive humidity in indoor housing. (P87.2.w1)
Population Control Measures BIRDS --
WATERFOWL --
CRANES Avoid overcrowding, which is stressful and may lead to increased parasite burdens. (P87.2.w1)
Isolation, Quarantine and Screening BIRDS --
WATERFOWL --
CRANES Isolate newly arrived birds and treat them for ectoparasites. (P87.2.w1)
Related Techniques
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