Respiratory disease in cattle workshop Flashcards
What is shipping fever
Occurs in groups of animals post weaning 6m-2yr
common after stress- e.g. after transport, mixing groups, sudden diet change
What pathogen commonly causes shipping fever
Mannheimia haemolytica
What causes ‘husk’
= Cattle lungworm
Dictyocaulus viviparus
List 5 examples of viral causes of bovine respiratory disease
Infectious bovine rhinotracheitis (IBR)
Parainfluenza 3 (PI3)
Bovine respiratory syncytial virus (RSV)
bovine viral diarrhoea virus (BVDV)
Malignant Catarrhal Fever (MCF)
List 5 examples of bacterial causes of bovine respiratory disease
Mycoplasma bovis
Mannheimia haemolytica
Pasturella multocida
TB (mycobacteria)
Contagious bovine pleuropneumonia (CBPP)
List 3 management factors that could cause bovine respiratory disease
Stocking density
Ventilation
Colostrum management
What causes IBR
bovine herpes virus 1
Describe the epidemiology of IBR
spread via aerosol - direct contact or shared air space
10-20 day incubation period
latency and infected for life
recrudescence with stress
what aged cows are mainly affected by IBR
growing age groups 6-24 months
List the main clinical signs of IBR
conjunctivits
watery eyes
milk drop
pyrexia (40C)
nasal discharge
hyperpnoea - taking deeper bretahs than normal
List some reproductive signs of IBR
decreased fertility
abortion - up to 100 days after resp signs
genital lesions (warts)
Describe how to diagnose IBR
Bulk milk antibody test
serology
nasal/conjunctival swabs for PCR
What clinical signs are different for IBR compared to MCF
No mouth/ nasal lesions or keratitis
What is the main control measure for IBR
Vaccinate to control clinical signs
(convential or marker vaccine)
live vs attenuated
what is required for accredited free IBR scheme
2 qualifying tests and regular monitoring (milk/blood)
required double fencing
What is required for vaccinated monitored free IBR accreditation
2 qualifying tests and regular monitoring (milk/blood)
vaccinate with marker vaccine
no double fencing needed
List 3 benefits of a accreditation free scheme for IBR
export trade
reduced disease/ impact of disease on farm
pedigree animals
Why are marker vaccines useful for IBR control
Differentiate vaccinated from infected, useful to eradicate disease
what are the benefits of a live vaccine over inactivated
rapid protection, especially when given intranasally
evidence that it is more effective
better in response to acute outbreak
If you had a dairy herd with a high bulk milk Ab for IBR but no clinical signs would you be more likely to use Live or inactivated vaccine
Inactivated
some evidence that it reduces shedding in latently infected animals
Describe RSV
Mainly affects calves
incubation= 2-5 days
pathology= necrotising bronchiolitis and interstitial pneumonia
Decribe PI3
mainly affects younger calves
highly contagious
more likely in stressed animals
What is the aetiology of malignant catarrhal fever (MCF)
Ovine herpes virus 2 which sheep carry without clinical disease
stress may increase shedding by sheep
How does MCF spread
aerosol, direct contact, contaminated feed/ water/ bedding
T/F cattle can spread MCF to other cattle
False
can only get it from sheep
List the clinical signs of MCF
pyrexia
enlarged lymph nodes
mucopurulent nasal and ocular discharge
corneal opacity
sloughing of oral and nasal mucosa (very characteristic)
what is the treatment for MCF
no licensed treatment or vaccine
almost always fatal- euthanasia only option
List 4 reservoirs for bovine TB
badgers
deer
ferrets
infected cattle
What are the main routes of infection for Bovine TB
ingestion or inhalation
What are the clinical signs of bovine TB
hardly ever seen due to testing regimes
soft productive cough
weight loss
LN enlargement
List the ways in which bovine TB can be tested for
SICCT skin testing
Blood testing (IFN gamma or antibody test)
Post mortem
What causes contagious bovine pleuropneumonia (CBPP)
Mycoplasma mycoides - bacterium
Where is CBPP generally seen
africa
eradicated from UK but is notifiable
What are the clinical signs of CBPP
pyrexia
increased resp rate and effort
weight loss
polyarthritis may be seen in affected calves
What are the clinical signs of mycoplasma bovis
chronic pneumonia
head tilt
head shake
arthritis
mastitis
How is mycoplasma bovis transmitted
shed in resp surface secretions
can be transmitted by aerosols
forms biofilm so can survive in environment well
How can mycoplasma bovis be diagnosed
serology/ PM (joint tap/milk)
Name an antibiotic you can’t use to treat a mycoplasma bovis infection and why
Penicillin- as mycoplasma does not have a cell wall which is what penicillin affects to kill the bacteria
How can mycoplasma be treated and why
Oxytetracycline as they don’t have a cell wall
Name 2 commensals of the URT in cattle
Mannheimia haemolytica
Pasteurella multocida
Describe M. haemolytica
gram -ve aerobic bacteria
involved in sporadic cases or outbreaks
Most commonly confirmed in suckler cows
can be primary or secondary invader
Describe P. multocida
gram -ve aerobic bacteria
more commonly isolated from calves
may be involved in sporadic cases or outbreaks
What causes Fog fever
typically causes disease when cattle move from sparse to lush, high protein pasture
L-tryptophan is ingested and converted into 3-methylindole which is pneumotoxic
Describe the clinical signs of fog fever
affected animals show severe respiratory distress without coughing
high mortality and animals often found dead
How to prevent fog fever
introduce cows to lush pasture slowly/ grazing pasture before it gets too lush
graze youngstock rather than adults on lush pasture
which lung lobe is generally the worst affected in pneumonia
cranio-ventral lung lobes
List some advantages and disadvantages of nasal swabs as diagnostic test for pneumonia
+ve
rapid test results
multiple animals can be sampled
-ve
viral infections are transient
bacterial isolates from some samples are dubious due to commensals
List some advantages and disadvantages of serology as diagnostic for pneumonia
+ves
High sensitivity as most respiratory pathogens induce a strong antibody response.
Less time-dependent as it can be effective in the relatively late stage of the disease
-ves
results are not available for >3 weeks
testing multiple samples can be expensive
List some advantages and disadvantages of PM examination as diagnostic method of pneumonia
+ves
Comprehensive and robust investigation
Easy to sample the lung and trachea and are ideal sites for sampling for further tests
-ves
*Diagnosis may be based on a few animals
Animals that die may not be representative of the herd problem
How can thoracic ultrasound be used in cases of pneumonia
Increasing the reliability of BRD diagnosis, especially in cases where there are few other clinical signs
Assessing recovery post treatment
Assessing the diagnostic ability of farm staff
Detecting calves in the early stages of disease
Ruling out chronic BRD in cases of poor growth rates and ill thrift.
Describe how to treat bovine respiratory disease
NSAIDs
Antibiotics e.g. Oxytetracycline, Amoxicillin
Electrolytes- help with dehydration
TLC