Download diagnostic show xlvets 14 9 11

B.V.D.
Bovine Viral Diarrhoea Virus
BVD
Highly contagious viral infection
Most infections have no clinical signs
Sero-conversion, virus elimination and
life-long immunity
BVD
Reproductive effects
Infection during pregnancy
Effect on foetus
Month 1
Embryo death
Month 2-4
Persistent Infection (PI)
Month 5-9
abortions, deformities, etc
BVD
Reduced immune function
Immuno-suppression
Enteric/Gut
Respiratory
Reproductive
Mastitis
Mucosal Disease
low morbidity / high mortality
BVD
Significance of PI
Most important source of infection in herd
May not be present when you search for it
Frequently unthrifty
May succumb to mucosal disease
May live for a long time in herd
Always antibody negative
BVD
Economics of infection
Initial outbreak
€19 - €600 per cow
Herd level
€31 -€100 / cow / year
National level
€15 - €20 / cow / year
BVD
Diagnosis of individual
Antibody
Virus
Sero-positive for life
Blood
Ear punch
may need to be confirmed
3 weeks later
BVD
Herd level screening
Adult herd
Dairy Bulk milk whole herd for Ab and Virus
Beef Bleed 15 non-vaccinated from each group
for Ab and Virus(pooled?)
Young stock
Bleed 5-10 home bred non-vaccinated 8-24
month old from each separate group for Ab and
Virus
BVD
Herd level diagnosis
Whole herd virus check
Calf ear punch
Bulk Tank Milk:Antibody
Virus
2 year project
National scheme may be launched in
near future
Non-vaccinated herd see
appearance of Ab
Vaccinated herd -monitor levels for
spikes
Shows presence of circulating virus in
milking herd
BVD
Risk factors for introduction
Purchase
Animal contact
Visitors
Equipment
Embryos
PI animal, Dam with PI,
Boundaries, Shows etc
BVD
Ideal world
Closed herd
No purchase of pregnant animals
Quarantine / testing of new
Avoid fence contact
Limit access on farm
disinfection, clothing
I.B.R.
Infectious Bovine Rhinotracheitis
IBR
Respiratory disease emerged in California in
early 50’s
UK in early 60’s
Mainland Europe in early 70’s
Ireland in 1989
IBR
Fever
Apathy
Anorexia
(Milk drop)
Respiratory
Reproduction
Death
4-5 days
Red nose, plaques, cough, nasal
discharge, conjunctivitis
Abortion (direct and indirect)
IBR
Establishes life-long latency in nerve tissue
Reactivation following stresses such as:transport, calving, weather, over-crowding,
corticosteroids.
IBR
Economics of infection
Reduction in milk production in antibody
positive cows
c. 0.92kg / day in one study
150kg / year (2%) in another
Loss of genetics value
IBR
Diagnosis of individual
Virus isolation
Deep intra-nasal swabs in clinically non-affected
animals
Antibody
Serum, milk
Antibody does not eliminate virus, infected for
life
Can do paired blood antibody 3 weeks apart to
demonstrate rising levels to indicate disease
IBR
Herd level screening
Bleed 5-8 animals for antibody from each
separate group
Bulk milk antibody
monitor for arrival or changes in Ab level
IBR
Control
Do nothing
Vaccinate in face of outbreak
Vaccinate to control clinical signs
Eradicate
IBR
Bio-security
Risk factors
Purchase
Animal contact
Visitors
Equipment
Boundaries, Shows etc
IBR
Ideal world
Closed herd
No purchase of animals
Quarantine / testing of new
Avoid fence contact
Limit access on farm
disinfection, clothing
IBR
Vaccintion
Live
Inactivated
Evidence divided on protocols
Johnes
Mycobacterium Avium Paratuberculosis
MAP
MAP
Chronic granulomatous enteritis of ruminants
Diarrhoea, weight loss, reduced milk yield,
death
MAP ingested from environment, colostrum or
milk
MAP
Economics of infection
Reduced milk production (600 – 2,200kg/lact)
Reduced constituents (fat, protein)
Increased mortality
Weight loss
Premature culling
Reduced slaughter value
Consumer worries
MAP
Diagnosis of individual
Culture
Faeces, milk, bulk tank, semen, dust
PCR
Semi-quantitative,
Antibody
Accuracy of ELISA (Se and Sp concerns)
False positives post TB testing
MAP
Herd level screening
Culture
Environmental dust, Bulk tank milk
BTM
Antibody
Se concerns (0.07 – 0.94)
PCR
lower level in milk
No test suitable to demonstrate freedom from infection.
MAP
Risk factors
Introduction
Purchase, manure/slurry, water
Transmission
Calving pen hygiene, udder cleanliness,
colostrum from positive cows, exposure to
faeces, mixed age housing
MAP
Low risk
High risk
Control
Danish system traffic light system
Green last 4 tests neg.
Red
2 or 3 pos from last 4
cull at end of season
Yellow
separate calving pen
remove calf immediately
colostrum from green cows
only
group by age
milk replacer and separate
housing
What can we do for you?
Interpret diagnostic tests
Plan herd diagnostic assessment
Bio-security advice
Vaccination planning