BRDC

Question 1

When are beef vs dairy cattle the most susceptible to BRDC?

Answer 1

Beef
- early feedlot phase
- early stocker phase

Dairy
- post-weaned calves
- bottle calves

Question 2

What are co-factors/stressers that facilitate development of BRDC?

Answer 2

Question 3

Where do Mannheimia organisms naturally occur?

Answer 3

In epithelial cells of tonsils of all calves

Question 4

Triad of reasons causing BRCD

Answer 4

1. Bovine lungs (small & poorly designed)
2. Mannheimia VFs (leukotoxin)
3. Management (manmade production stressors)

Question 5

Why is prevention the most effective method for controlling Mannheimia?

Answer 5

The organism naturaly occurs in the tonsils of ALL calves and reactivate during stressful events -> preventing stressors = #1 goal

Question 6

Pre-conditioning vs Conditioned programs

Answer 6

Question 7

Ideal vaccine timing for BRDCs?

Answer 7

Prior to stressor events (which is also 7-10 days before start of respiratory signs)

Question 8

What are the 4 categories of calves?

Answer 8

Question 9

What is the most imperative measure for bringing in newly received cattle to pasture?

Answer 9

Provide plenty of water!

Study showed only significant pre-disposing factor for developing resp. dz = increased PCV = dehydration

Question 10

Clinical signs of BRDC

Answer 10

1. depressed
2. off feed / decreased appetite
3. fever
4. coughing
5. mucopurulent nasal discharge

Depressed: ears down, head extd., isolated

Question 11

How long should you wait to switch ABX if no improvement of clinical signs?

Answer 11

48h

Abx used to treat can stay in the lungs anywhere from 3-28 days

Question 12

Metaphylaxis

Answer 12

Mass medication of all calves @ high risk of developing BRDC

less calves get sick, monitoring is longer (those that do take longer)

Prophylaxis and metaphylaxis involve administering antimicrobials to ‘healthy’ individuals to ‘prevent’ infections. Prophylaxis is a perceived ‘risk’, whereas metaphylaxis could be a definable ‘hazard’.

Question 13

3 clinical signs of Mycoplasma infection

Answer 13

1. Pneumonia (severe)
2. Joint issues (severe lameness)
3. Ear infection

pus-filled trachea; lungs diffused w/ abscesses

Question 14

Common issue with mycoplasma-pneumonia abx treatment?

Answer 14

Treatment relapses

Question 15

Diptheria
- causative agent
- dx

Answer 15

• disease of the larynx in cattle, caused by Fusobacterium necrophorum
• dx = honking sounds on inspiration audible from 15 ft away; lung sounds > trachea sounds