More Related Content More from Sandra Baxendell (12) CAE Caprine Arthritis Encephalitis 1. Presentation on CAE or Caprine
Arthritis Encephalitis (Big Knees or
Caprine Retrovirus)
by Dr Sandra Baxendell to the Qld branch of the
DGSA on 30th June 2012
Laidley, Qld
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2. Caprine Retrovirus or CAE Virus
= a slow virus
RNA only (not DNA, but converts to DNA within
cells)
retrovirus family (like HIV-AIDS)
Subgroup Lentivirus like sheep disease Maedi
Visna (= Ovine Progressive Pneumonia)
attached to monocytes and macrophages
(types of white blood cells) but only multiply in
the later
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3. CAE virus also found in
Cells of the udder (mammary) – also that CAE
positive goats more likely to develop bacterial
mastitis
Cells of the uterus
Large numbers of viruses in inflamed brain,
spinal cord, lung, joints, and mammary gland
cells of CAE positive goats
Smaller numbers in lung, liver, spleen, lymph
nodes, lining the vessels of brain, synovium,
intestines, kidneys & thyroid
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4. Clinical Signs
Chronic Arthritis which starts as a peri-arthritis
and progresses to deformed limbs and wasting
“Hard Udder” - udder feels like a smooth stone
under the skin with only a small amount of milk
produced
Chronic interstitial pneumonia with wasting and
difficulty breathing
Nervous signs (generally in kids)
Note most goats get only 1 form
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6. CAE exported from developed
countries
Australian dairy goats gave CAE to
NZ
Western countries have given CAE to
Fiji, Kenya, Mexico, New Zealand
and Peru plus probably others
Africa is generally free
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7. Risks
Feeding pooled milk to all kids
Dairy goats, rarely in fibre & ferals
Age (older goats more likely to be
positive)
Large herds
Milking & kidding herds
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8. CAE Transmission
Milk and colostrum is main source of
infection
Horizontal risk low, but still possible, if not
milking or kidding
Single intra-mammary dose can transmit
CAE – milking machines?
Some via ET but not all methods
Sheep overseas have acted as carriers
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9. Handy Hints
Wash kids when catch them at birth
Keep cows colostrum (JD free) in
freezer
Milk negative does first
Elastoplast doe's teats
Induce does within 7days of due date
so kid on weekends (ask your vet)
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10. Blood Tests in General
Precision = repeatability and
variance (bias)
Accuracy = trueness
But general public just needs to ensure use a
NATA accredited laboratory
NATA= National Association of Testing
Authorities see www.nata.asn.au
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11. Blood Tests in General 2
Sensitivity – picks up levels of antibodies so
can have false negatives in early stages or if
no antibodies produced e.g. close to giving birth
or antibody production capacity is reduced
Specificity – measures the type of antigen
so can have false positives if picks up too wide
a range of antigens
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12. CAE Blood Tests
ELISA – automated, recommended
AGID -recommended, good specificity but is
generally less sensitive
PCR - picks up viral DNA, but lentiviruses are
very genetically variable so less sensitive than
ELISA . Not a screening test nor recommended
Western Blot (no protocol, research lab only)
Radio immune types (no protocol, research lab
only)
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13. Vet Labs System & CAE
The World Organisation for Animal Health
(OIE) – the former Office International des
Epizooties - AGID or ELISA are the prescribed
tests in their Terrestrial Manual (Chapter 2.7.3
Australia and NZ's Animal Health committee's
via their lab subcommittee (SCAHLS)
recommend AGID or ELISA
Australian Vet labs should be NATA
accredited and take part in proficiency tests
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14. Animal Health Committee- Subcommittee on Animal
Health Laboratory Standards (SCAHLS)
SCAHLS = reps from Australian Government, state
and territory governments, CSIRO-AAHL, veterinary
schools at universities & the private labs
SCAHLS establishes, implements and monitors
professional & technical standards by dealing with
quality assurance, skills, & the validation of new tests.
Publishes the Australian & New Zealand Standard
Diagnostic Procedures.
Runs international proficiency testing (30 labs Aust,
NZ, USA , Asia, Europe etc)
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15. Does test type matter?
Do you ask your doctor or pathology
office what blood test type you are
going to get for yourself when getting
tested for any disease/condition?
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16. CAE blood tests
Work best in herds with high virus loads
Individual goats can give false negatives if
their immune systems are reduced in
capacity. So do not test within 1 month
either side of kidding or after vaccination
or if have clinical CAE
Goats with low virus levels can become
intermittently negative
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17. So what does this mean?
Tests need to be backed up with clinical
examination of the herd by a vet
Tests need to be considered a herd, not
an individual test; i.e. don't test just the
goat you want to buy, but ensure the
whole herd it comes from has been tested
Whole herd tests need to be repeated
initially each year
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18. The Bottom Line
CAE can be eradicated from goat
herds by catching kids for a separate
new herd and then blood testing these
kids to pick up any unlucky enough to
be positive
CAE control schemes have worked
around the world
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19. CAE Control Schemes
NSW the best
WA -CAE is no longer a notifiable
disease & accreditation scheme
stopped in 2006 as goat industry was
not interested in it when it moved to
full cost recovery.
UK – run by Dairy Goat Society not
government
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20. Successes
Smallpox and Rinderpest eradicated from
world
Bovine Pleuro-pneumonia, TB &
Brucellosis eradicated from Australian
cattle
EBL eradicated - Australian dairy cattle '12
Alpaca and Johne's Disease
Visna eradicated from Iceland
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21. Why Bother?
Consumer perceptions
Animal welfare
More mastitis, udder infections & higher SCC
Herds viral loads will increase and more health
problems then occur
Dairy goats will become the pariah of the whole
goat industry
Sheep industry concerns re MV and CAE
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22. Warning for Goat Buyers
Both NZ and UK have warnings on their
websites e.g.
http://www.allgoats.com/health.htm#How
%20often%20should%20I%20test
NZ “ Warning to New Goat Buyers
There are a number of significant diseases that can affect
goats in New Zealand, such as Johnes Disease and
Caprine Arthritis Encephalitis (CAE). If a goat displays
signs of these diseases, it can be very distressing for the
owner..............................
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23. So could CAE be eradicated from Qld and
Australia like the Dairy Cattle Industry did with a
similar slow virus (Enzootic Bovine Leucosis) ?
YES
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24. What is needed
Clear vision with awareness campaign
Commitment to control schemes in goats
Ideally survey to determine how
widespread, but how to fund a survey?
Once a high level of control, then
eradication from states and then Australia
Ideally a bulk milk test + blood tests – but
need funding for R&D to check it works?
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25. Opportunities
DOOR = Do Our Own Research
Universities with students looking for
projects & partners
Government and their agencies with
good track record in eradications if all
parts of industry supports it
Seek allies for funding - who benefits
if CAE is eradicated?
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26. Opportunity for Qld
Queensland has only 1 goat herd
quarantined for Johne's disease,
despite lots of testing
Johne's disease is not established in
Qld sheep or cattle
If Qld could also eradicate CAE, live
export of goats could benefit
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27. Margaret Mead quote
“Never doubt that a small group of
thoughtful committed citizens can
change the world. Indeed, it is the
only thing that ever has.”
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