| Summary Information |
| Diseases / List of Miscellaneous /
Metabolic / Multifactorial Diseases / Disease summary |
| Alternative Names |
Congenital
malformation. See also:
|
| Disease Agents |
Include:
- Genetic factors
- Temperature extremes
- Irradiation (X-rays)
- Natural plant alkaloids
- Excessive selenium
- Various chemical toxins, including formaldehyde, organophosphates such as
parathion and diazinon and herbicides such as trifluralin and paraquat)
- Specific nutrient imbalances:
- Vitamin A deficiency
- Excess vitamin A
- Vitamin B12 deficiency
- Folic acid deficiency
- Zinc deficiency)
(J2.20.w2, J7.14.w5, J7.15.w8, B12.5.w10, B119.w1). |
| Infectious
Agent(s) |
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| Non-infectious
Agent(s) |
|
| Physical
Agent(s) |
|
| General Description |
Abnormal
development of downies during incubation - present at hatching. Presents a variety of
syndromes:
- Limb deformities including duplication of hind toes, enlarged middle toe
with terminal phalanges and nail duplicated, toes abnormally positioned and of abnormal
proportions in mallards Anas platyrhynchos (J7.14.w5, J7.17.w2).
- Unilateral or bilateral premaxillary deformities, with grossly narrowed
premaxillary area (exaggerated 'spoonbill' shape) in cinnamon teal Anas cyanoptera,
southern pochard Aythya erythrophthalma, greater snow goose Anser
caerulescens atlanticus (J3.74.w1).
- Shortening of upper (maxillary) bill in mallard Anas platyrhynchos;
also in mute swan Cygnus olor (J3.74.w1).
- Acrania (absence of frontal and parietal bones and associated meninges,
brain herniated outside skull), plus shortened upper bill in mallard Anas
platyrhynchos and chiloe wigeon Anas sibilatrix (J3.74.w1).
- Encephalocoele/meningocoele: domed frontal and occipital area, normal
meninges with overlying squamous epithelium lacking in down , but no bone over dorsum of
brain in a mandarin Aix galericulata (J2.20.w2);
similar condition plus shortened upper bill in mallard Anas platyrhynchos (J3.74.w1).
- Intraventricular septal defect in a mandarin Aix galericulata (J2.20.w2).
- Twins sharing a yolk (which neither could absorb), muscovy Cairina
moschata (J7.17.w2).
- Vertebral abnormalities including missing vertebrae, spina bifida and
scoliosis, sometimes with associated body and limb deformities, in mule ducks (white Pekin
x Muscovy); scoliosis was common in the white Pekin ducks Anas platyrhynchos
domesticus from which these ducklings were bred (J5.12.w3).
- Cervical vertebrae abnormalities resulting in torticollis and/or
incoordination. N.B. may survive and live normally, although euthenasia
may be required if severely affected (B11.38.w6).
- Severe twisting and deformity of legs, trumpeter swan Cygnus
buccinator (J7.S1.w4)
- Imperforate vent, trumpeter swan Cygnus buccinator (J7.S1.w4).
- Possibly congenital cataract noted in a one-week-old Carolina (wood duck)
duckling (J6.6.w3).
- Hydroencephalocele in mallard duckling from a female with Vitamin B12
deficiency (Vitamin B12
Deficiency) (B16.19.w1).
- Foot malformation in mallard Anas platyrhynchos embryo, due to
selenium toxicity (B12.5.w10).
- Anencephaly and oedema in mallard Anas platyrhynchos embryo
following herbicide application to the eggshell (B12.5.w10).
- Shortened axial skeleton, cervical lordosis, subcutaneous oedema, in
mallard Anas platyrhynchos duck embryo following application of low-level
organophosphate insecticide to eggshell (experimental) (B12.5.w10).
- Rachischisis and encephalitis in mallard Anas platyrhynchos duck
embryo following exposure to crude oil (experimental (B12.5.w10).
|
| Further Information |
- Most non-experimental cases of congenital abnormality have involved a
single malformed individual in an otherwise normal clutch. An exception is the finding of
varying foot deformities in four of eleven mallard ducklings in one brood.
- Genetic factors and toxins in the environment have been suggested as
possible causes.
(J3.74.w1, J7.14.w5, J7.15.w8, J7.17.w2) |
| Techniques linked to this disease |
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| Host taxa groups /species |
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| Disease has been reported in either the wild or in captivity
in the following WATERFOWL Species: |
[N.B. Miscellaneous
/ Traumatic Diseases tend to be under-reported and the majority are likely to affect all
waterfowl species, given exposure to the related disease agents/factors.]
- Mandarin Aix galericulata (encephalocoele and ventricular septal
defect) (J2.20.w2).
- Mallard Anas platyrhynchos (foot deformities, polydactyly)
(J7.14.w5).
- Cinnamon teal Anas cyanoptera, southern pochard Aythya
erythrophthalma, greater snow goose Anser caerulescens atlanticus
(premaxillary deformities- 'spoon-billed'), mallard Anas platyrhynchos,
mute swan Cygnus olor (shortening of upper (maxillary) bill); mallard
(meningocoele plus shortened upper bill) (J3.74.w1).
- Muscovy duck Cairina moschata (twins sharing yolk sac) (J7.17.w2).
- Mule ducks Anas platyrhynchos domesticus x Cairina moschata
domesticus, and Pekin ducks Anas platyrhynchos domesticus (J5.12.w3).
- Trumpeter swan Cygnus buccinator: imperforate vent in one
cygnet, seveerly twisted and deformed legs in another, Minnesota, USA (J7.S1.w4).
- Carolina (wood duck) duckling, one week old, cataract - possibly
congenital (J6.6.w3).
- Mallard Anas platyrhynchos with hydroencephalocele, associated
with vitamin B12 deficiency.
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| Disease has been reported in free-ranging populations of the
following WATERFOWL Species: |
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