Waterfowl DiseasesWaterfowl DiseasesUpdate – Past 15 YearsUpdate – Past 15 Years
Nicole BeaverNicole Beaver
Avian CholeraAvian Cholera Avian BotulismAvian Botulism Duck viral enteritis (DVE)Duck viral enteritis (DVE) West Nile Virus West Nile Virus Avian Vacuolar Myelinopathy (AVM)Avian Vacuolar Myelinopathy (AVM) Avian InfluenzaAvian Influenza
Avian CholeraAvian Cholera
Most important disease in N. Most important disease in N. American waterfowlAmerican waterfowl
Kills quickly – 6-12 hoursKills quickly – 6-12 hours First diagnosed in 1940First diagnosed in 1940 Outbreaks in new areas have Outbreaks in new areas have
become more frequent in the past 20 become more frequent in the past 20 yearsyears
Avian Cholera – Recent Avian Cholera – Recent ResearchResearch
Little is known about the Little is known about the interactions between the host, the interactions between the host, the agent, and the environmentagent, and the environment
Outbreaks tend to occur in Outbreaks tend to occur in wetlands/populations that have wetlands/populations that have suffered previous outbreakssuffered previous outbreaks
Agent could survive in infected Agent could survive in infected wetland OR in carriers birdswetland OR in carriers birds
Recent Research cont.Recent Research cont.
Sacramento National Wildlife RefugeSacramento National Wildlife Refuge Water and sediments tested for Water and sediments tested for
Pasteurella multocidaPasteurella multocida The bacteria was found in samples taken The bacteria was found in samples taken
during or soon after outbreaksduring or soon after outbreaks Samples 1-3 months post-outbreak did not Samples 1-3 months post-outbreak did not
contain the bacteriacontain the bacteria P. multocida P. multocida probably doesn’t survive probably doesn’t survive
long enough in the environment to long enough in the environment to cause the recurring outbreakscause the recurring outbreaks
Recent Research cont.Recent Research cont.
Carrier birdsCarrier birds Lesser snow geese from Wrangle Island, Lesser snow geese from Wrangle Island,
Russia and Banks Island, CanadaRussia and Banks Island, Canada Blood samples collected each summer and Blood samples collected each summer and
tested for antibodiestested for antibodies 8% of blood samples from the Banks Island pop. 8% of blood samples from the Banks Island pop.
Contained antibodies (post-outbreak)Contained antibodies (post-outbreak) 3% with antibody from Wrangle Island (no outbreak)3% with antibody from Wrangle Island (no outbreak)
More birds infected than once thoughMore birds infected than once though Some survive infection – could become carriersSome survive infection – could become carriers More research is neededMore research is needed
Avian BotulismAvian Botulism
Botulism has occurred naturally for Botulism has occurred naturally for centuries, however, changes in habitat use centuries, however, changes in habitat use may be increasing the severity of may be increasing the severity of outbreaksoutbreaks
Cleaning up carcasses is not completely Cleaning up carcasses is not completely effectiveeffective More birds die than can be found and removedMore birds die than can be found and removed Money going toward cleanups could be better Money going toward cleanups could be better
spent in more research, or in conserving more spent in more research, or in conserving more wetland habitatwetland habitat
Botulism - ResearchBotulism - Research
Connection between botulism and Connection between botulism and blue-green algae bloomsblue-green algae blooms
Describe water quality and weather Describe water quality and weather during botulism outbreaksduring botulism outbreaks
Increase understanding of carcass-Increase understanding of carcass-maggot cycles and identify other maggot cycles and identify other possible carrierspossible carriers
Duck Virus EntiritisDuck Virus Entiritis
1993 outbreak in Finger Lakes, New 1993 outbreak in Finger Lakes, New YorkYork
Some exposed birds become carriersSome exposed birds become carriers Appear healthy but can transmit the Appear healthy but can transmit the
disease to othersdisease to others A vaccine does exist, but is used A vaccine does exist, but is used
primarily in breeder ducksprimarily in breeder ducks
West Nile VirusWest Nile Virus New York City New York City
area – 1999area – 1999 Spread through Spread through
U.S., Canada, U.S., Canada, Mexico, and Mexico, and CaribbeanCaribbean
FlavivirusFlavivirus Transmitted by Transmitted by
mosquitoesmosquitoes Affects about 250 Affects about 250
species of bird species of bird
Symptoms of WNVSymptoms of WNV
WeaknessWeakness Stumbling/tremblingStumbling/trembling Head tremorsHead tremors Can’t flyCan’t fly Easily approachableEasily approachable
WNV ControlWNV Control
Mainly aimed at preventionMainly aimed at prevention Mosquito controlMosquito control
Public reports of dead birdsPublic reports of dead birds
Avian Vacuolar Avian Vacuolar Myelinopathy (AVM)Myelinopathy (AVM)
Recently discovered Recently discovered neurological diseaseneurological disease
Mainly affects bald Mainly affects bald eagles and American eagles and American coots coots Also confirmed in Also confirmed in
mallards, buffleheads, mallards, buffleheads, ring-necked ducks, and ring-necked ducks, and Canada geeseCanada geese
Occurs from November Occurs from November to March as populations to March as populations migrate in and out of migrate in and out of areasareas
Arkansas, Georgia, N. Arkansas, Georgia, N. and S. Carolina, and S. Carolina, suspected in Texassuspected in Texas
AVM SymptomsAVM Symptoms Lack of muscle Lack of muscle
controlcontrol Fly into walls, crash-Fly into walls, crash-
land, appear land, appear intoxicated, swim intoxicated, swim upside-downupside-down
Affected birds appear Affected birds appear healthy and are alert healthy and are alert and aware of and aware of surroundingssurroundings
Lesions in myelin of Lesions in myelin of brain and spinal cordbrain and spinal cord
CauseCause
UnknownUnknown Not parasitic, fungal, bacterial, viral, Not parasitic, fungal, bacterial, viral,
or prionor prion Associated with submerged aquatic Associated with submerged aquatic
vegetationvegetation Onset is dose-dependentOnset is dose-dependent Suspect cause is a toxin – natural or Suspect cause is a toxin – natural or
man-mademan-made
ResearchResearch
Exposure is site specific and seasonal.Exposure is site specific and seasonal. Birds with brain lesions may not Birds with brain lesions may not
exhibit symptoms.exhibit symptoms. Brain lesions were produced in red-Brain lesions were produced in red-
tailed hawks in laboratory conditions tailed hawks in laboratory conditions when fed tissue from affected coots.when fed tissue from affected coots.
An invasive aquatic plant, hydrilla, An invasive aquatic plant, hydrilla, produced brain legions in some produced brain legions in some laboratory mallards.laboratory mallards.
AVM – Future ResearchAVM – Future Research Continue to monitor AVM at lakes where Continue to monitor AVM at lakes where
the disease occurs and at nearby lakes the disease occurs and at nearby lakes without disease. without disease.
Characterize environmental factors at the Characterize environmental factors at the sites where AVM has occurred. These site sites where AVM has occurred. These site characterizations will be instrumental for characterizations will be instrumental for developing risk assessment models and may developing risk assessment models and may generate hypotheses regarding generate hypotheses regarding environmental conditions conducive for environmental conditions conducive for AVM outbreaks. AVM outbreaks.
Identify the causative agent of AVM. Identify the causative agent of AVM.
Avian InfluenzaAvian Influenza
Virus which spreads through contact Virus which spreads through contact with feces, saliva, or nasal dischargewith feces, saliva, or nasal discharge
Mainly found in poultry and wild Mainly found in poultry and wild birds (including some waterfowl), birds (including some waterfowl), but can affect mammals as wellbut can affect mammals as well
When the virus jumps species, it When the virus jumps species, it mutatesmutates
SymptomsSymptoms
Low pathogenic forms are often Low pathogenic forms are often undetectedundetected
Symptoms may be as slight as ruffled Symptoms may be as slight as ruffled feathers and a small decrease in egg feathers and a small decrease in egg productionproduction
Highly pathogenic forms can affect Highly pathogenic forms can affect multiple internal organsmultiple internal organs 90-100% mortality90-100% mortality 48 hour incubation48 hour incubation
Avian InfluenzaAvian Influenza
Low or highly pathogenicLow or highly pathogenic Depends on strainDepends on strain
Strain H5N1 is highly pathogenicStrain H5N1 is highly pathogenic Mortality in more than 80 bird speciesMortality in more than 80 bird species 98 human fatalities98 human fatalities
Low pathogenic forms have occurred Low pathogenic forms have occurred in North Americain North America
Peak occurrence in N. American Peak occurrence in N. American ducks is late summer and early fallducks is late summer and early fall
H5N1H5N1
Highly contagious among birdsHighly contagious among birds Does not usually spread to humansDoes not usually spread to humans Close contact with infected birdsClose contact with infected birds
ControlControl Ban on birds and bird products from Ban on birds and bird products from
affected countriesaffected countries
Current SituationCurrent Situation
The outbreak is not expected to The outbreak is not expected to diminish in affected areasdiminish in affected areas
Ducks are shedding more virus for Ducks are shedding more virus for longer periods of time, without longer periods of time, without showing signs of the illnessshowing signs of the illness
There is little natural immunity to There is little natural immunity to this strain among humansthis strain among humans