Bovine Respiratory Pathogens

Question 1

What are the main bacterial pathogens

Answer 1

Mannhemia haemolytica - normal flora

Pasteruella multocida - normal flora

histophilus somni - commensal of bovine MMs

mycoplasma bovis - commensal

Question 2

Mannheimia haemolytica:
- clinical findings?

Answer 2

severe acute fibrinonecrotic bronchopneumonia

coagulative necrosis due to leukotoxin production

Question 3

Mannheimia haemolytica:
- dx?

Answer 3

culture/PCR w/ deep naso-pharyngeal swab

Question 4

Pasteruella multocida
- clinical findings?

Answer 4

less fuliminating fibrous to fibrinopurulent bronchopnuemonia

limited lung necrosis

suppurative bronchitis and brnchiolitis

Question 5

Histophilus somni
- clinical findings/signs

Answer 5

• sudden death, important cause of mortality in feedlot calves
• 7-20d on feed –> arthritis, suppurative bronchopneumonia
• 30-60d on feed –> pleuritis, pericarditis, myocarditis, thrombotic meningoencephalomyelitis, sepitcemia

Question 6

Histophilus somni
- dx?

Answer 6

culture - joint fluid, pleural fluid, lung, heart

hisotologicla lesion - localized infiltration of neutrophils

Question 7

Mycoplasma bovis
- who is typically affected?

Answer 7

typically a chronic pneumonia in feedlots of cows 30-60d on feed

Question 8

Mycoplasma bovis
- clinical findings

Answer 8

caseous abscesses, affects multiple large joints

Question 9

Mycoplasma bovis
- tx

Answer 9

tulthromycin, enrofloxacin

Question 10

BRSV:
- Clinical findings

Answer 10

diffuse interstitial pneumonia

honking sound

subpleural and interstitial empysema

atelectasis