Bovine Respiratory Flashcards
Which bacteria are commonly found as secondary invaders after a primary pathogen insults the respiratory tract?
Mannheimia haemolytica
Pasteurella multocida
Name 2 other non-viral pathogens implicated in respiratory disease in cattle and comment on whether they commonly occur as other clinical presentations
Histophilus somni (also seen as meningoencephalitis) Mycoplasma spp (esp M.bovis); also implicated in aggressive mastitis, metritis, septic arthritis, otitis media
What happens to a calf <4 weeks of age, when the ambient temperature drops below its LCT?
Calf uses energy shivering to maintain body temp -> fails to gain weight, may lose weight
Mucociliary function may be affected -> reduction in defences of the respiratory tract
Which of these NSAIDs is available in a form with a zero milk withhold period? Ketoprofen (Curacef) Carprofen (Rimadyl) Meloxicam (Metacam) Flunixin (Resflor)
Ketoprofen
Carprofen
What differentials would you consider in a cow in a group of beef cattle kept at grass which is breathing heavily and showing profuse hypersalivation?
'Fog fever' (reaction to fructans in grass) Acute pasteurellosis (check for recent stress) Oesophageal obstruction Heat stroke (time of year?)
How is the lungworm vaccine administered and when?
What does it comprise?
‘Huskvac’
Vaccinate healthy animals of 8 weeks of age and older. Can be used during pregnancy. Give 25ml orally.
First vac: 2 doses 4 weeks apart, then a single vaccine prior to each season’s turnout
Comprised of virus antigens
Where are the lungfields on a cow?
Triceps cranially
Attachment of the ribs to the vertebral column dorsally
An imaginary line joining the point of the elbow to the 11th intercostal space
Small lung volume for body size
Give some design issues with the bovine lung
Small lung volume for body size
Large dead space
No collateral ventilation of alveoli
Alveoli are easy to damage and difficult to recover
Poorly developed fibrinolytic systems
Early and substantial vasoconstriction of arteries and arterioles
Give some problems with large dead space in the bovine lung
Limited respiratory reserve
Reduced phagocytic activity in the dead space
Decreased clearance of bacteria
Give some problems with no collateral ventilation of alveoli
No ‘pores of Kohn’ or bronchiole anastomoses, ie if part of lung is compromised, air can’t move to other parts of lung to aerate it
Give some problems with early vasoconstriction of arteries and arterioles
Early vasoconstriction in pneumonia is intended to maintain arterial BP, but also cuts off blood supply to the pneumonic lung
Give some problems with cows having a poorly developed fibrinolytic system
Persistent fibrinous exudate
Lung scarring
What happens to colostrum if left at room temperature?
Bacterial growth
Which part of the respiratory tract do parainfluenza virus and RSV (respiratory syncytial virus) affect?
LRT
Which part of the respiratory tract does IBR (bovine herpes virus) affect?
URT
Give some clinical signs of IBR (bovine herpes virus)
Pyrexia Milk drop Ocular/nasal discharge Conjunctival hyperaemia Coughing
Describe the 3 major types of bovine herpes virus
BHV-1: respiratory and repro systems (abortion)
BHV-2: IPV (infectious pustular vulvo-vaginitis) (no abortion)
BHV-4: endometritis
Give some clinical signs of mycoplasma bovis
Conjunctivitis Pneumonia Septic arthritis Otitis media (head tilt if chronic) Mastitis
How is Mycoplasma bovis transmitted?
Direct cow-cow contact, metritis to udder, resp aerosols, fomites
Give some commensal agents that cause pneumonia
Mannheimia haemolytica
Mycoplasma bovis
Pasteurella multocida
When is BRD most common?
Winter
UV light kills viruses -> less sun in winter
According to guidelines, how many animals should share the same airspace?
No more than 30