Drowning (with special reference to Waterfowl and notes on Hedgehogs, Bears and Lagomorphs)

Disease Summary

Alternative Names (Synonyms)

• --

Disease Type

Infectious/Non-Infectious Agent associated with the Disease

Infective "Taxa"

Non-infective agents

• Oil

Physical agents

• Heavy waves / Rapid water flow
• Ice formation
• Restriction of normal movement
• Salinity high
• Surface tension of water decreased by surfactants
• Temperature - low ambient

References

Disease Author

Major References / Reviews

Code and Title List

Other References

Code and Title List

Hedgehogs:
B255.1.w1, B255.2.w2, B257.2.w3, B259.w9, D75, D79, D84, D87, D88, D90, W51.July2002.WEH2, W93.July2002.WEH3, W99.July2002.WEH1, W99.July2002.WEH2, V.w26

Bears:
J417.20.w1, V.w91

Lagomorphs:
J3.150.w5, J40.8.w1, J47.9.w1

Detailed Clinical and Pathological Characteristics

General

Clinical Characteristics

• Skin: Pelage or plumage is usually obviously wet. (B20.14.w11)
• Respiratory:
  • Breathing may be difficult, with excessive respiratory effort, or may have ceased. 
  • Fluid sounds may be heard on auscultation.
  • Manipulation of the animal may result in excess water being passed out of the nose/mouth from the trachea or oesophagus. (B20.14.w11, V.w5)

• Found dead in water or on shore.
• May be encrusted with salt, tangled in underwater obstructions (e.g. fishing nets, odd-shaped holes in banks below water level), covered with oil, or found after melting of ice.

(J1.22.w2, J1.23.w2, J7.14.w2, J7.S1.w5, P10.28.w1).

• Generally found dead in water bodies such as steep-sided garden ponds. (B255.1.w1, B259.w9)

Incubation

Mortality / Morbidity

Pathology

• May be few gross lesions.
• Skin and hair/feathers: Wet, or if dried, matted. 
• Respiratory: 
  • Water in the mouth or nasal cavities.
  • Excessive frothy fluid in the respiratory tract (including the air sacs in birds).
  • Lungs are usually distended and slightly congested.
  • Sub-pleural petechiae may be found.
• Gastro-intestinal: Fluid may be found in the oesophagus and stomach.

  (B20.14.w11)

Histopathological lesions:

• Respiratory:
  • Inhaled fluid may be found to contain diatoms and other aquatic organisms.(B20.14.w11)
  • There may be inflammatory responses in the lungs. (B20.14.w11)

• Feathers wet, or matted if dried out; may be oiled.
• Water in buccal/nasal cavities. Water in trachea, lungs and air-sacs. Lungs reddened.
• Aquatic organisms may be found on microscopic examination of inhaled fluids.

(J1.22.w2, J1.23.w2, J7.14.w2, B20.14.w11, P10.28.w1).

Human Health Considerations

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

• White-faced whistling duck Dendrocygna viduata adult, swan goose Anser cygnoides juvenile, scoter Melanitta spp. juvenile (J7.4.w1)
• Common Pochard Aythya ferina (J7.14.w2)
• Spotted Whistling Duck Dendrocygna guttata, Chilean Pintail Anas georgica spinicauda, Mallard Anas platyrhynchos, Cinnamon Teal Anas cyanoptera, Common Shoveler Anas clypeata, Australian White-eye (Hardhead) Aythya australis, Fulvous whistling Duck Dendrocygna bicolor, Salvadori’s Duck Anas waigiuensis, European Green-winged teal Anas crecca crecca, Mallard Anas platyrhynchos (J7.14.w3).
• Cygnet (species not given) in a collection in the UK (J7.43.w1).
• Swan(s) (J7.43.w2).
• Diving ducks (B36.47.w47).
• Ducks (B37.x.w1).
• Common teal Anas crecca ducks by mating drakes, if too many kept in an enclosure (B40).
• Canada geese Branta canadensis, lesser snow goose Anser caerulescens caerulescens, probably Ross's goose Anser rossii, terminal water aspiration associated with salt encrustation (J1.23.w2).
• Tundra swan Cygnus columbianus in the USA, associated with strong surf (J1.22.w2, J7.S1.w5).
• Mallard Anas platyrhynchos (J7.14.w3)
• New Zealand scaup Aythya novaeseelandiae, during mating (B139).

Hedgehogs

• Hedgehogs have been found drowned in a small, vertical-sided garden pond with the water surface two inches (5cm) below the rim. (B255.1.w1)
• Hedgehogs may be found drowned in garden ponds with steep plastic sides, or in outdoor swimming pools. (B259.w9)

Bears

• An Ursus maritimus - Polar bear in a zoo drowned when the bear became trapped under ice in its pool during unusually severe winter weather (prolonged freezing temperatures and a blizzard). (V.w91)

Lagomorphs

• Two juvenile Sylvilagus floridanus - Eastern cottontail were found in a lily pond close to their nest and were presumed to have drowned. (J40.8.w1)
• Three radiotagged adult Oryctolagus cuniculus - European rabbit in a population in Spain died in burrows flooded during heavy rain; over the whole study period flooding caused the death of 1.5% of the tagged adults. (J3.150.w5)
• Drowning and exposure to damp in flooded burrows was a major cause of death of kits during observations of rabbits restricted to a large enclosure. (J47.9.w1)

Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken). Host species with further information available are listed below:

WATERFOWL Host Species List

• Anas clypeata - Northern shoveler
• Anas crecca - Common teal
• Anas cyanoptera - Cinnamon teal
• Anas georgica - Yellow-billed pintail
• Anas platyrhynchos - Mallard
• Anser caerulescens - Snow goose
• Anser cygnoides - Swan goose
• Anser rossii - Ross's goose
• Aythya australis - Hardhead
• Aythya ferina - Common pochard
• Aythya novaeseelandiae - New Zealand scaup
• Branta canadensis - Canada goose
• Cygnus columbianus - Tundra swan
• Dendrocygna bicolor - Fulvous whistling-duck
• Dendrocygna guttata - Spotted whistling-duck
• Dendrocygna viduata - White-faced whistling-duck
• Salvadorina waigiuensis - Salvadori's teal

MAMMALS:

• Erinaceus europaeus - West European Hedgehog
• Oryctolagus cuniculus - European rabbit
• Sylvilagus floridanus - Eastern cottontail
• Ursus maritimus - Polar bear

[N.B. Miscellaneous / Traumatic Diseases tend to be under-reported and the majority are likely to affect all species, given exposure to the related disease agents/factors.]

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

• Canada geese Branta canadensis, lesser snow goose Anser caerulescens caerulescens, probably Ross's goose Anser rossii, terminal water aspiration associated with salt encrustation (J1.23.w2).
• Tundra swan Cygnus columbianus in the USA, associated with strong surf (J1.22.w2, J7.S1.w5).
• Mallard Anas platyrhynchos (J7.14.w3)

Hedgehogs:

• Hedgehogs have been found drowned in a small, vertical-sided garden pond with the water surface two inches (5cm) below the rim. (B255.1.w1)
• Hedgehogs may be found drowned in garden ponds with steep plastic sides, or in outdoor swimming pools. (B259.w9)

Lagomorphs

• Two juvenile Sylvilagus floridanus - Eastern cottontail were found in a lily pond close to their nest and were presumed to have drowned. (J40.8.w1)
• Three radiotagged adult Oryctolagus cuniculus - European rabbit in a population in Spain died in burrows flooded during heavy rain; over the whole study period flooding caused the death of 1.5% of the tagged adults. (J3.150.w5)

Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken). Host species with further information available are listed below:

WATERFOWL Host Species List

• Anas platyrhynchos - Mallard
• Anser caerulescens - Snow goose
• Anser rossii - Ross's goose
• Branta canadensis - Canada goose
• Cygnus columbianus - Tundra swan

MAMMALS:

• Erinaceus europaeus - West European Hedgehog
• Oryctolagus cuniculus - European rabbit
• Sylvilagus floridanus - Eastern cottontail

[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.]

General Information on Environmental Factors/Events and Seasonality

• Ice and salt encrustation of aquatic birds such as waterfowl are likely to be seen in the autumn and winter as temperatures fall.
• Drowning of waterfowl and other aquatic birds may be associated with severe weather conditions, such as storms and heavy surf.
• Drowning is also also associated with loss of waterproofing of the plumage or pelage (fur) of (particularly aquatic) birds and mammals, for example due to oil contamination.
• Drowning following falling through ice is associated with environmental factors producing ice cover , but of insufficient thickness to hold the weight of the animal on its surface.

(B20.14.w11, B36.47.w47, B36.51.w51, P10.28.w1)

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

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

General Information on Investigation / Diagnosis

• The affected animal may have been found within a pond, lake, swimming pool or other water-holding body.
• Wet hair or feathers (if these have dried, then they are likely to be matted).
• Presence of water in the mouth or nasal cavity.
• Respiratory signs following water inhalation; fluid sounds associated with the respiratory system.
• Excess water may be passed out of the trachea and/or oesophagus if the animal is manipulated.
• At post mortem examination excess frothy fluid in the respiratory tract (including in the air sacs of birds). Lungs usually distended, slightly congested and sometimes with sub-pleural petechial haemorrhages. 
• Aquatic organisms such as diatoms may be detected within the inhaled fluid. 

(B20.14.w11, V.w5)

• History, feathers wet, or matted if dried out, water in respiratory tract at post mortem examination.
• Other signs of excessive mating activity, such as feather-picking and bruising, may be evident in birds drowned during mating.

(B20.14.w11, V.w5)

• History and Documentation - General
• Physical Examination of Birds - General
• Physical Examination of Mammals
• Necropsy of Birds - General
• Necropsy of Mammals

Similar Diseases (Differential Diagnosis)

• For birds found in sea or on shore: trauma (pounding into shore by surf).
• N.B. Drowning may be seen as the terminal event in diseases such as Avian Botulism when birds become unable to keep their head out of water.

Specific Medical Treatment

General Nursing and Surgical Techniques

• Hold upside down to drain water from respiratory tract. 
• Stimulate by rubbing and apply artificial respiration; intubate and administered oxygen if available. 
  • Continue artificial respiration or supply of oxygen until spontaneous breathing resumes.
• Intravenous sodium bicarbonate may be useful to counter acidosis. 
• Keep warm. Consider whether treatment is required for hypothermia (See: Chilling - Hypothermia).
• Give prophylactic antibiotics to reduce the risk of pulmonary infection.

(B20.14.w11)

• Treatment and Care - General

Preventative Measures

Environmental and Population Control Measures

WATERFOWL 

• For captive waterfowl, ensure ponds have sides with shallow slopes allowing easy exit from the water, particularly if small ducklings will be using the pond, or diving ducks which do not walk well.
• Use e.g. running water to keep ponds from icing over in cold weather.
• If downies are raised with constant access to bathing water (preferred particularly for seaducks and stiff-tails), care in construction and monitoring is required. An alternative which may be used for dabbling ducks and geese is to raise with access only to a shallow water dish, with pebbles in the bottom initially. In this case it will be necessary to introduce the birds to water gradually (only shallow water initially) to allow waterproofing to develop, and be watchful and ready to intervene when they are first given access to deeper water.

(B13.46.w1, B94, B95, B97, V.w5).

• Build ponds with at least one side sloping gently to allow easy exit from the water.
• Ensure steep-sided ponds and other structures which may hold water have a ramp allowing animals which fall in to climb out and/or large submerged bricks or stones onto which animals may step, providing a firm surface from which to climb out of the water
• Cover ponds with a well-fitting plastic mesh cover to prevent animals falling into the water.
• Provide outdoor swimming pools with a float (wooden or polystyrene) onto which animals may climb.
• If possible cover outdoor pools at night.
• See: Garden Management for Hedgehogs (Erinaceus europaeus) - Ponds / Lakes / Watercourse / Swimming Pools

(B255.2.w2, B257.2.w3, D75, D79, D84, D87, D88, D90, W51.July2002.WEH2, W93.July2002.WEH3 W99.July2002.WEH1, W99.July2002.WEH2, V.w26)

• Preventative Medicine for Birds - General
• Environmental and Population Management - General
• Garden Management for Hedgehogs