Bovine Pneumonia

Question 1

List the viral causes of pneumonia

Answer 1

IBR, PI3, RSV, (BVD)

Question 2

LIst the bacterial agents involved in pneumonia

Answer 2

Mannheimia haemolytica
Pasteurella multocida
Histphilus somni
Mycoplasma dispar/bovis

Question 3

Name the parasitic cause of pneumonia

Answer 3

Dictyocaulus viviparus

Question 4

Describe the pathogenesis of chronic ‘cuffing’ pneumonia

Answer 4

Mycoplasma
Insidious onset
Can predispose to secondary bacterial infection
Causes a necrotising pneumonia, well demarcated foci of caseous necrosis, lesions are more circular and friable than those with M. haemolytica/H. somni
See joint lesions in ~50% calves

Question 5

What are the clinical signs of cuffing pneumonia?

Answer 5

Mild form - occasional low grade coughing, tachypnoea, BAR
Severe form - frequent cough, tachypnoea (>60bmp), hypernoea, exercise intolerance, decreased growth rate, adventious lung sounds over cranioventral fields, mild pyrexia

Question 6

How is cuffing pneumonia treated?

Answer 6

Mild cases may resolve w/o tx, usually self limiting

Question 7

What are the clinical signs of acute enzootic/viral pneumonia?

Answer 7

Dull
Anorexic
Tachypnoea (

Question 8

What can viral pneumonia predispose to?

Answer 8

Secondary bacterial infection and chronic/suppurative pneumonia

Question 9

Describe the presentation of IBR

Answer 9

Lots of animals affected simultaneously
Ocular and nasal discharge
Pyrexia
Acute laryngotracheitis on PM

Question 10

Describe the pathogenesis of pasteurellosis/shipping/transit fever

Answer 10

Seen esp in weaned, suckled calves
Peak incidence Sep - Dec
Most cases within 4 weeks of housing due to stress

Question 11

Which pathogens are involved in pasteurellosis?

Answer 11

Mannhaemia haemolytica, Pasteurella multocida, Histophilus somni

Question 12

Describe the pathogenesis of chronic suppurative pneumonia

Answer 12

Inevitable end point in most cases
Decreased weight gain
Repeated bouts of acute pneumonia
Tx often unsuccessful therefore cull

Question 13

What is the general tx protocol for pneumonia (except chronic)

Answer 13

Ab and NSAID
Additional therapy - vaccination, steroids (licensed to reduce inflammation in cattle), fluids/diuretics, clenbuterol, TLC

Question 14

Which animals in a group should be treated?

Answer 14

Threshold temp of 39.6 degrees

Anything obviously sick

Question 15

Describe disease caused by M. haemolytica

Answer 15

Initiating agent of pasteurellosis
2 strains - A1 and A6 (vaccines against both)
Often present in nasal cavity of healthy carriers
Mixing of stressed and carrier animals precipitates dz
Dx - hx, BAL culture, PM (lung lesions in acute cases), tonsilar and nasal isolates

Question 16

Describe disease caused by P. multocida

Answer 16

Present in nasal cavity of most animals
Secondary pathogen usually
Primary pathogen = type B
Rapidly isolated from lung lesions in untreated animals BUT isolates from URT may not be significant

Question 17

Describe disease caused by H. somni

Answer 17

Present in U/LRT of healthy cattle
Can cause thromboembolic meningioencephalitis
Difficult to isolate

Question 18

What are the clinical signs of pasteurellosis?

Answer 18

Dull
Anorexic
Tachypnoea (60-100bpm), hypernoea
Marked pyrexia