Download CWD in Cervidae

Chronic Wasting Disease in
Cervidae
Clifford F. Shipley, DVM, DACT
Attending Veterinarian for Agricultural
Animals
University of Illinois
My Background
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Nodaway, Iowa
Deer hunting @ 12: bow, shotgun
Northwest Missouri State University
Iowa State University
Practice
Virginia-Maryland Regional College of Veterinary Medicine
ASDIC, Ltd.
Yoder Feeds
University of Illinois, College of Veterinary Medicine
Attending Veterinarian for Agricultural Animals
Exotic/Non Traditional Species/ Alternative Livestock
ILDFA, NADeFA, AASRP, IL Livestock Advisory Board
Raise deer (mule deer, WTD, wapiti)
“Expert”
• 1. Very skillful; having
much training and
knowledge in some
special field.
• 2. A guy far away from
home with a box of
slides.
• 3. A “person” far away
from home with a
computer and a
projector.
• 4. My wife is not around
History of CWD
• Colorado 1967
– “wild” deer elk used for research in Foothills
Wildlife Research Facility, Fort Collins
• TSE status in 1978
• Wyoming Sybille Wildlife Research Facility
1979; captive elk
• Colorado wild elk 1981
• Colorado mule deer 1985
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Wyoming: wild mule deer 1985
Saskatchewan: captive elk 1996
South Dakota: captive elk 1997
Oklahoma: captive elk 1998 (from MT)
1999
– NE: wild mule deer
– MT herd destroyed
• 2000: wild Saskatchewan mule deer
• 2001: SD WTD; NE captive WTD
2002-present
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Widespread testing
Meetings
Rules
Regulations
Fear
Accusations
State and Federal Action and Funding
What is CWD?
• Prion Disease
– “is an infectious agent composed of protein in a
misfolded form.”
– "Chronic Wasting Disease Alliance (www.cwdinfo.org)"
– Other “prion” diseases
• Scrapie
– (sheep and goats)
• Bovine spongiform encephalopathy
– cattle
• Mink encephalopathy
• Humans
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Creutztfelt-Jakob (CJD)
Variant Creutzfelt -Jakob (vCJD)
Familial Creutzfelt-Jakob (fCJD)
Sporadic Creutzfelt-Jakob (sCJD)
Gerstmann-Straussler-Scheinker syndrome (GSS)
Fatal familial insomnia (FFI)
Kuru
• Ostrich (non infectious)
• Cat (feline spongiform encephalotpathy (FSE)
• Nyala, oryx, greater kudu (exotic ungulate
enephalopathy) EUE
Prion general information
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“protein”
Not bacteria, virus, fungus, etc.
May bind with soil particles
Resistant to sterilization
– Heat, radiation, formalin, proteases
– Dependent on protein hydrolysis
• Bleach, caustic soda, acidic detergents
• Ozone, pressurized steam
Other disease theories
• Spirochete
• Mineral deficiency
– Cu
– Others?
• Virus
• Bacterial
• Multifactorial (requires agent + genetic
susceptibility: scrapie)
• Other???
Where did it come from?
• Been here all along theory
– Didn’t test for it
– Didn’t recognize disease symptoms
– Didn’t understand epidemiology/biosecurity
– Increased testing
• Jumped specie theory
– Colorado research: scrapie?? Other??
– Then dispersed thru sale and transfer of animals
• Spontaneous theory
– Mis-folded protein
– Genetic
• Other?
Genetics
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Scrapie: genetic link
Elk: genetic link
Human: genetic link
WTD: ?
Moose: ?
Red deer: ?
Clinical signs: CWD
• White-tailed deer, mule deer, elk (wapiti), red
deer, moose, black-tail, Columbia, sika
– Ataxia
– Dementia
– Weight loss
– Behavioral changes
– Pneumonia
– Death
Transmission
• Oral
– Feces
– Urine
– Saliva
– Muscle
– Nervous tissue
– ???
• Experimental infections
– injection
Get Well Soon
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Grooming
Mineral licks
Feeding stations
Social animal
– Family groups
– Habitat
– Bedding areas
• Migration
– Elk: long migration routes, wintering areas
– deer: migration, rut, dispersal
• Deer eat bones/gut piles of dead deer
• Scavenger theory:
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Crows
Coyotes
Other
Man
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Transport of infectious material
Taxidermy
Improper handling/disposal of infectious material
Wild carcass transport and disposal
– Composting
– Distribution to zoo/captive animals
Chronic Wasting Disease
Alliance
Diagnosis
• Brain sampling
– Obex (brain stem)
– Histology
– Immunohistochemistry (IHC)
• Lymph nodes
– Retropharyngeal
– Others?
• Other tests
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Rectal biopsy
Serology
Third eyelid
PCR?
Tonsilar biopsy
• Need accurate live animal test
Treatment
• NONE
• Speculation if other etiologies
– Antibiotics
– Mineral supplementation
– Anti-inflammatories
– ????
Control:
• Movement
– Animals
• Source
• Testing
• Monitoring
– Carcasses
– Taxidermy
– Scavengers
– other
• Vaccination
– University of Saskatoon
– Clinical trials currently underway
• Canada
• US
• Genetic selection
– Evolutionary
– Controlled biological testing
Future of CWD
• Canadian Wildlife Federation
– Dr. Paul James
• Societal questions
– Perceptions
– Reality
– Alternative Livestock Industry
– Conservation/Wildlife
– HSUS/PETA
– Resources
My Conclusions
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Only affects certain cervidae species
Does not affect other livestock
Does not affect man
Can not eradicate
Endemic
Spreading
Federal and State Programs in place
Does not affect populations