Respiratory disease in Cattle Flashcards
environment factors
housing ventilation stocking density mixing sharing air space with other age groups weather changes
air quality
ventilation dependent
check ammonia levels from the bedding at calf height
bovine respiratory disease (BRD) in young calves
dairy herd housed calves removed form mothers weaned at 50-80d chronic or acute (enzootic pneumonia)
enzootic pneumonia
usually group affected
decr feed intake
calves are dull
coughing dry/moist is 1st sign
main pathogens
mycoplasma dispar, bovis + canis ureaplasma spp bovine viral diarrhoea virus (BVDV) para-influenza virus 3 (PI3) bovine respiratory syncytial virus (BRSV) infectious bovine rhinotracheitis (IBR) bovine coronavirus
bacteria
manheimia haemolytica A1 + 6
pasteurella multocida
arcanobacterium pyogenes
histophilus somni
management of an outbreak
treatment
environment
PME of dead calves
identify pathogens
treatment of pneumonia
antibiotics
NSAIDs
treatment rules
data sheet when to repeat muan safety meat + milk withdrawal time injection site
effect of prolonged use of NSAIDs
serious damage to GIT (abomasal ulcers) + renal failure
identification of pathogens
sample calves early in disease
PME
transtracheal wash, BAL, nasopharyngeal swab, serology, faecal exam
bronchoalveolar lavage (BAL) - technique + tests run
tube via nostril into trachea
flush in saline then withdraaw
send for viral isolation + bacterial culture + sensitivty
swabs
guarded nasopharyngeal swabs
bacteriology + virology
specific transport media for bacteria, virus, mycoplasma
paired serology
for viruses
2 clotted smaples 14-21 days apart
slow - 4 weeks
antibody titres confused by previous vaccine + maternal antibodies
IBR, bovine herpes virus (BHV) - clinical signs
pyrexia
conjunctivitis
coughing
tracheitis
BHV-1.1
resp disease
IBR
BHV-1.2
genital form (rare)
infectious pustular vulvovaginitis (IPV)
infectious pustular balanoposthitis
clinical syndromes
resp disease - rhinitis, tracheatis + conjunctivitis - all can progress to pneumonia ocular form encephalitis abortion repro failure latent infection
latency
BHV-1 becomes latent after infection resides in trigeminal ganglion can last forever can reactivate after a long time recrudescence due to stress can't be detected
IBR control
know herd status
biosecurity
vaccination
eradication if possible
IBR vaccine
vaccines work well
will prevent disease if given before exposure
may reduce circulating virus levels
may reduce excretion
live vaccines
rapid immunity
usually 1 dose
young animals may need 2 due to maternally derived antibodies (MDA)
intranasal vaccine
local secretory IgA + interferon
rapid protection
DIVA
marker vaccine
to differentiate between infected + vaccinated
