Test 3: 46, 48,49 bovine Flashcards
3 components of respiratory disease in cows
management
viral diseases
bacterial disease
there should be a minimum of — air changes per hour for proper ventilation
4
2 functions of ventilation
remove CO2
remove heat and moisture
natural vs mechanical ventilation systems
natural: open roof vents- allow hot air to rise and exit, can cause drafts
mechanical- fans in closed barns, inlets=outlets
— are used for ventilating group housing for calves
positive pressure tubes- push Co2 and warm air out and prevent draft
three pulmonary defense mechanisms
mucociliary defense system
pulmonary alveolar macrophages
secretory system
mucociliary defense system will —
warms and filters incoming air
removes dust and organism
very efficient- 90% effective
— are found in the lower respiratory tract and eat pathogens
— efficiency
pulmonary alveolar macrophages
50% efficiency
neutrophils only enter in response to infection
secretory system of the respiratory tract work by activating — immunity
cell mediated immunity
and
local immunity: IgA and interferon(viral response)
serum AB less important
where is accessory lung lobe in cows
right lung
right cranial bronchus comes off — in the cow
before tracheal bifurcation
anatomy of cow lungs
left side: 2 lobes (cranial has two parts)
right side: 4 lobes (cranial has two parts), cranial, middle, ventral and accessory
basal lung metabolism uses — bovine lung capacity
45%
horses and humans use 20% of basal- need to take big breath to hear
what side to listen to cows lungs
right sound- use more of lung to breathe, may seem harsh
narrow lung field: 13 ribs
4 major bovine viral respiratory diseases
IBR: infectious bovine rhinotracheitis
PI-3: parainfluenza Type 3
BRSV: Bovine respiratory syncytial virus
BVDV: bovine viral diarrhea virus
IBR is caused by
herpes type 1 virus
more than 80% of cattle are sero-positive
latent infections are common
IBR clinical signs
high fever > 105
mild dyspnea
white nasal plaques (red nose)
WBC normal
mild/rapid recovery if NO 2ndary bacterial infection
infectious bovine rhinotracheitis- herpes virus
rare presentations of IBR
encephalitis- with meningitis, non-purulent
fatal septicemia- calves < 1 week old, peritonitis
balanoposthitis- plaques on penis and prepuce
abortion- autolysis of fetus
infectious bovine rhinotracheitis- herpes virus
IBR diagnosis
- serology- virus neutralization, paired samples (3 weeks apart)
- virus isolation
- fluorescent antibody
- PCR
infectious bovine rhinotracheitis- herpes virus
treatment for IBR
antiinflammatory- flunixin meglumine
aspirin boluses
meloxicam
infectious bovine rhinotracheitis- herpes virus
prevention of IBR
foundation vaccine
intranasal: best interferon producer, rapid onset, no abortions
modified live: + abortions, lonest lasting immunity, recommened for all youngstock
killed vaccine: safest, two doses then annual booster
infectious bovine rhinotracheitis- herpes virus
IBR has high seroprevalence, is not very pathogenic alone, WBC profile is —, — plaques, predisposes to — pneumonia, — syndromes and can cause —
normal
white
bacterial
many
abortions and lead to shipping fever (2ndary bacterial infection)
infectious bovine rhinotracheitis- herpes virus
PI-3 presents with
mild symptoms- nasal discharge
not pathogenic alone, usually in combo with pasturella or mannheimia bacteria
parainfluenza 3 virus
vaccinate for PI-3?
yes included in IBR vaccines
short term immunity- 3 months
given before stressful event such as shipping
BRSV stands for
bovine respiratory syncytial virus
— are both from the paramyxovirus family
PI-3
BRSV
bovine respiratory syncytial virus
how is BRSV spread
latent infection
spread from dam at birth, when she is stressed
bovine respiratory syncytial virus
diagnosis of BRSV
serology NOT useful
passive immunity not protective
BRSV occurs in —
short incubation 3-5 days
high incidence: 2-5 month old calves
passive immunity NOT protective
bovine respiratory syncytial virus
two syndromes of BRSV
atypical interstitial pneumonia
ARDS: acute respiratory distress syndrome
bovine respiratory syncytial virus
clinical signs of BRSV
high fever
↑ salivation
air under skin- SQ emphysema
ARDS: respiratory distress- open mouth breathing
can recover in a few weeks, but if they become to stressed when treating can die
may develop bacterial infection(30% may die)
bovine respiratory syncytial virus
how to treat BRSV
prevent stress
prevent 2ndary bacterial infection- give antibiotic
30% may die from becoming to stressed during treatment
bovine respiratory syncytial virus
diagnosis of BRSV
very hard to do
virus very fragile and difficult to grow
also only present during early clinical course
fluorescent antibodies
immunohistochemistry
necropsy of BRSV will show
interstital pneumonia
syncytial cells (giant cells)
bovine respiratory syncytial virus
BRSV vaccination
included in combo vaccine but does not work?
passive immunity not protective
serum antibodies not protective
requires 3-4 week booster
BVDV stands for
bovine viral diarrhea virus
clinical signs of BVDV
diarrhea
immunosupressive
fever
mucosal erosions
abortion
PI (persistant infection) calves (gestation 40-120 days)
bovine viral diarrhea virus
vaccinate BVDV?
yes- part of combo
very effective
