Mycoplasma bovis

Question 1

What is Mycoplasma bovis?

Gross lung lesions?

Answer 1

•Chronic pneumonia & polyarthritis in feedlot cattle
• Mastitis in dairy cows 
•Otitismedia,cutaneous
abscesses, …
Caseonecrotic bronchopneumonia

Question 2

How do you test for BVDV (e.g. in the study discussed)

Answer 2

• Immunohistochemistry: lung, heart, skin • Isolation: lung, lymph node, ileum, spleen

Question 3

How do you test for mycoplasma bovis (e.g. in the study discussed)

Answer 3

• Culture: lung, joint • Immunohistochemistry: lung

Question 4

Mannheimia haemolytica - pathologic description

Answer 4

Coagulation necrosis in
Mannheimia haemolytica
• Flat, not raised
• Irregular, “map-like”
• Red or tan, with white border • Not friable

Question 5

If the lung & the liver feel the same, what do you have?

Answer 5

Mycoplasma or mannheimia haemolitica

Question 6

If the lung feels rubbery?

Answer 6

Something causing interstitial

Question 7

Mycoplasma bovis - pathologic description

Answer 7

Caseous necrosis in
Mycoplasma bovis
• Raised
•Circular
•White
•Friable
•Dry (c.f. abscesses)

Question 8

Days to death between pneumonic pasteurellosis vs. mycoplasma bovis

Answer 8

Fibirinous pneumonia - die quickly, mycoplasma, goes on

Question 9

If you find mycoplasma when culturing lungs, what does that mean?

Answer 9

*Isolation of Mycoplasma bovis is not sufficient for the diagnosis

Question 10

Does BVDV have a correlation between manheimia & M. bovis?

Answer 10

BVDV infection is prevalent in both mannheimia and m.bovis infections.

Question 11

How do animals recover when in the chronic pen?

Answer 11

60% may completely recover
Some recover for early salvage slaughter
Some may encounter complications (unable to feed/water, condition loss, recurrent pneumonia even manheimia pneumonia)

Question 12

Managing calves with CPPS?

Answer 12

• Place in non-competitive situation
• Assist to rise for feed and water
• Well bedded and protected from elements
• Euthanize if unable to rise (for 24 hr)
• “Traffic-cop” chronic pen at least weekly
– home, retreat for pneumonia, euthanize if continual weight loss over 3 weekly weighings (2 wk period)

Question 13

CPPS: Putative control measures

Answer 13

• Minimize respiratory disease
– prevaccinated (especially for BVD), if feasible – metaphylaxis on arrival when appropriate
– keep chronics separate from new pulls
– pull aggressively on day 3 post-metaphylaxis – reassess carefully at appropriate time post-tx
• Avoid metaphylaxis?
– Seems to avoid CPPS but requires good facilities and dedication and, of course, is only done by those confident and dedicated
• Vaccinate for M. bovis? X
– 16,000 head AB trial in ‘94 demonstrated absolutely no benefit

Question 14

CPPS: Sequence of Events

Answer 14

• Change in BVD virus?
• Change in Mycoplasma bovis?
• Excellent control of Mannheimia haemolytica (shipping fever)?
– “Nature abhors a vacuum” Eugene Janzen
– Implementation of metaphylaxis?
• Selecting resistant Mycoplasma bovis? • False sense of security?
– Excellent newer, long-acting antibiotics for UBRD? • Failure to monitor non-responders?
• Mycoplasma resistance?

Question 15

Managing calves with CPPS

Answer 15

• Place in non-competitive situation
• Assist to rise for feed and water
• Well bedded and protected from elements
• Euthanize if unable to rise (for 24 hr)
• “Traffic-cop” chronic pen at least weekly
– home, retreat for pneumonia, euthanize if continual weight loss over 3 weekly weighings (2 wk period)

Question 16

Why Is This Happening?

Answer 16

• Change in BVD virus?
• Change in Mycoplasma bovis?
• Excellent control of Mannheimia haemolytica (shipping fever)?
– “Nature abhors a vacuum” Eugene Janzen
– Implementation of metaphylaxis?
• Selecting resistant Mycoplasma bovis? • False sense of security?
– Excellent newer, long-acting antibiotics for UBRD? • Failure to monitor non-responders?
• Mycoplasma resistance?