Bovine Respiratory Disease

Question 1

Describe Mannheimia haemolytica

Answer 1

Family Pasteurellaceae
• Small, facultatively anaerobic, nonmotile, gram-negative rods or
coccobacilli that do not form endospores.
• Mannheimia haemolytica is one of the most important pathogens of
domestic cattle.
• Primary bacterial agent responsible for bovine pneumonic
pasteurellosis, also known as “shipping fever”
• Accounts for approximately 30% of the total cattle deaths globally.
• A recent study estimated the annual economic loss to the U.S. beef
cattle industry at $640 million.

Question 2

What is the main problem with vaccinations and treatment for M. haemolytica?

Answer 2

• Many serotypes are present, so its difficult to universally vaccinate

Question 3

How is M haemolytica spread?

Answer 3

• inhaling droplets, direct nose-to-nose contact, ingesting nasal discharge-contaminated feed

Question 4

What are the clinical signs of M haemolytica?

Answer 4

depression, anorexia, fever, nasal
discharge, and a soft, moist cough, become apparent 6 to 10 days after a
stressful episode.

Question 5

What is the prognosis for shipping fever?

Answer 5

Poor

- Mortality rate is high, survivors have irreversible lung damage

Question 6

What is a distinguishing feature of shipping fever?

Answer 6

• Severe fibrinous pluropneumonia

- Seen in the cranioventral lung lobes