Diseases / List of Parasitic Diseases / Disease description:

Acanthocephala Infection in Waterfowl

INFORMATION AVAILABLE

GENERAL INFORMATION

CLINICAL CHARACTERISTICS & PATHOLOGY

INVESTIGATION & DIAGNOSIS

TREATMENT & CONTROL

SUSCEPTIBILITY & TRANSMISSION

ENVIRONMENT & GEOGRAPHY

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General and References

Disease Summary

WATERFOWL Infection with acanthocephalans (thorny-headed worms) which may result in enteritis and emaciation, sometimes peritonitis.

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Alternative Names (Synonyms)

  • Acanthocephaliasis
  • Thorny-headed worm infection

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Disease Type

 Parasitic - Thorny-headed Worms

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Infectious/Non-Infectious Agent associated with the Disease

Acanthocephalans (thorny-headed worms) including Filicollis anatis, Polymorphus altmani, Polymorphus obtusus, Polymorphus botulus, Polymorphus minutus. Worms attach to intestinal wall with retractile proboscis.

Infective "Taxa"

Non-infective agents

--

Physical agents

-- Indirect / Secondary

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References

Disease Author

Debra Bourne
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Major References / Reviews

Code and Title List

B9.6.w1, B11.39.w7, B12.55.w1, B14, B15, B36.33.w33, B37.x.w1
J7.50.w1
J36.41.w1, J36.44.w1
V.w3, V.w11

Other References

Code and Title List

J1.11.w5, J1.13.w6, J1.13.w7, J1.16.w8, J1.17.w6, J1.22.w4
J14.11.w1

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Clinical Characteristics and Pathology

Detailed Clinical and Pathological Characteristics

General

WATERFOWL Non-specific signs of lethargy and emaciation associated with loss of nutrients to parasites and damage to intestinal wall.

Clinical Characteristics

WATERFOWL Non-specific signs: lethargy, rapid weight loss, anaemia and emaciation, stunting, death (J36.44.w1, B11.39.w7, B9.6.w1, B36.33.w33, B37.x.w1).

Incubation

WATERFOWL Generally considered to be a chronic disease (B15), but lethal infections have occurred in ducklings at just a few days old (V.w3, V.w11).

Mortality / Morbidity

WATERFOWL Sometimes epizootics; may cause high mortality (B15, B36.33.w33, B37.x.w1).

Pathology

WATERFOWL Gastro-intestinal tract - Enteritis, sometimes haemorrhagic. White nodules visible on serosal surface of intestine, each containing proboscis of an acanthocephalan. Mucosal surface, intense inflammation around embedded proboscis of acanthocephalans (white-to-bright yellow/orange parasites, 0.5-1cm long), which are firmly attached to the intestinal wall. Severe granulomatous haemorrhagic enteritis with heavy infections. Parasites may penetrate gut wall and cause adhesions between loops of intestine and/or peritonitis (J7.50.w1, J36.44.w1, B11.39.w7, B12.55.w1, B14, B15, B36.33.w33, B37.x.w1).

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Human Health Considerations

None (B37.x.w1).

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Susceptibility / Transmission

General information on Susceptibility / Transmission

WATERFOWL
  • Common eiders Somateria mollissima appear to be particularly susceptible, due to feeding habits (ingestion of intermediate hosts). Cygnets also appear susceptible, and sometimes domestic ducklings.
  • Eider ducklings often have concurrent renal coccidiosis (Renal Coccidiosis) and other endoparasite infections.
  • Transmission by ingestion in intermediate hosts (crustaceans), particularly fresh water shrimp Gammarus spp.

(B9.6.w1, B11.39.w7, B15, B36.33.w33, B37.x.w1).

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

Disease has been reported in:
  • Common eiders Somateria mollissima, cygnets, domestic ducklings (B15, B36.33.w33).
  • Mute swans Cygnus olor in Scotland (J7.50.w1, J36.41.w1, J36.44.w1).
  • Blue duck Hymenolaimus malacorhynchus ducklings in a collection in the UK - fatal infection at only a few days old (V.w3, V.w11).

Infection has also been reported in:

  • Wild Trumpeter swan Cygnus buccinator in Canada, with concurrent gizzard worm, intestinal fluke and cestode infection (J14.11.w1).
  • Wild Black-bellied whistling-ducks Dendrocygna autumnalis in southern Texas, USA (J1.11.w5).
  • Wild Cinnamon teal Anas cyanoptera in southwest Texas, USA (J1.13.w6).
  • Wild Northern shovelers Anas clypeata in southwest Texas (J1.13.w7).
  • Wild Mallard Anas platyrhynchos, American wigeon Anas americana, Green-winged teal Anas crecca and Blue-winged teal Anas discors in Oklahoma, USA (J1.16.w8).
  • Wild Green-winged teal Anas crecca in southwest Texas, USA (J1.17.w6).
  • Wild Mexican duck Anas platyrhynchos diazi (J1.22.w4).

WATERFOWL Host Species List

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

Disease has been reported in:
  • Common eiders Somateria mollissima (B15).
  • Mute swans Cygnus olor in Scotland (J7.50.w1, J36.41.w1, J36.44.w1).

Infection has also been reported in:

  • Wild Trumpeter swan Cygnus buccinator in Canada, with concurrent gizzard worm, intestinal fluke and cestode infection (J14.11.w1).
  • Wild Black-bellied whistling-ducks Dendrocygna autumnalis in southern Texas, USA (J1.11.w5).
  • Wild Cinnamon teal Anas cyanoptera in southwest Texas, USA (J1.13.w6).
  • Wild Northern shovelers Anas clypeata in southwest Texas, USA (J1.13.w7).
  • Wild Mallard Anas platyrhynchos, American wigeon Anas americana, Green-winged teal Anas crecca and Blue-winged teal Anas discors in Oklahoma, USA (J1.16.w8).
  • Wild Green-winged teal Anas crecca in southwest Texas, USA (J1.17.w6).
  • Wild Mexican duck Anas platyrhynchos diazi (J1.22.w4).

WATERFOWL Host Species List

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Environment/Geography

General Information on Environmental Factors/Events and Seasonality

Epizootics are usually associated with stresses such as food shortage, stress of migration or breeding (particularly female eiders while or just after brooding, versus in males and immatures in late winter/early spring). May be common in certain localized geographical areas (B14, B15, B36.33.w33).

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

Worldwide (B36.33.w33).

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

--

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General Investigation / Diagnosis

General Information on Investigation / Diagnosis

WATERFOWL Fecal examination can show presence of infection (spindle-shaped eggs, containing embryo with rostral circlet of hooks). Post mortem examination is necessary to show acanthocephalan infection (cylindrical, non-segmented, often bright yellow/orange) as the cause of death or a contributory factor, based on the number of parasites present (more than 100 P. botulus may be considered a heavy infection; numbers may reach 1-2000) and degree of intestinal damage associated (B11.39.w7, B12.55.w1, B14, B15, B36.33.w33, B37.x.w1).

N.B. Inspection of Gammarus spp. (intermediate hosts) may reveal the presence of the larval parasites - e.g. orange Polymorphus minutus, which is visible within the gammarids to the naked eye (V.w3).

Related Techniques
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Similar Diseases (Differential Diagnosis)

WATERFOWL Gizzard worm infection (Gizzard Worm Infection), echinuariasis (Echinuriasis (Acuariasis)) (B37.x.w1).
  • Differentiate worms found at post mortem examination (cylindrical, non-segmented, often bright yellow/orange) from cestodes (B12.55.w1).

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Treatment and Control

Specific Medical Treatment

WATERFOWL Treatment is impractical in wild birds. In captive birds, use of anthelmintics: ivermectin (single dose 200g/kg body weight oral or subcutaneous), benzimidazoles such as fenbendazole (single oral dose 20mg/kg), levamisole (25-50mg/kg oral or subcutaneous single dose) may be useful (B11.39.w7, B15, B36.33.w33, B37.x.w1).
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General Nursing and Surgical Techniques

WATERFOWL --
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Preventative Measures

Vaccination WATERFOWL --
Prophylactic Treatment

WATERFOWL

For information on routine parasite control see Preventative Medicine for Birds - Parasite screening and Routine Control Measures
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Environmental and Population Control Measures

General Environment Changes, Cleaning and Disinfection

WATERFOWL

Impractical for wild birds. Manage waterfowl to avoid waterfowl using water areas with large numbers of the crustaceans which act as intermediate hosts for acanthocephalans, particularly freshwater shrimp Gammarus spp, or drain infected waters (B11.39.w7, B15, B36.33.w33, B37.x.w1).
Population Control Measures WATERFOWL Keep young birds on water areas not used by other birds and therefore less likely to have large numbers of infected intermediate hosts (B15, B36.33.w33).
Isolation, Quarantine and Screening WATERFOWL --
Related Techniques
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