Exam 2: Respiratory disease

Question 1

What is required to set up a disease?

3 Prongs

Answer 1

• Microbiological agents (pathogen)
• Environment
• Host

Question 2

What makes a host susceptible to disease?

Answer 2

• Stress: increased cortisol levels
• Age: Don’t mix old with the young
• Immune status
• Nutrition
• Production type/stage
• Breed
• Previous exposure
• Origin
• Genetics
• Sex
• Disposition
• Weight

Question 3

How does the environment make an animal susceptible to disease?

Answer 3

• Weather: Hot, cold, wind, mud
• Altitude
• Herd: Pregnant, weaning, social structure
• Housing

Question 4

How does the pathogen (microbiological agent) make an animal more susceptible to disease?

Answer 4

• Pathogen profile
• Host
• Virulence
• Number/ amount
• Mode of transmission

Question 5

How does respiratory disease set in?

Answer 5

1. Initial viral infection (most, not all, respiratory diseases start with a viral infection)
2. Virus attacks the muco-ciliary elevator (deactivates the cilia): First line of defense
3. Secondary bacterial infection results

Question 6

What is BRDC?

Answer 6

Bovine Respiratory Disease Complex
* Shipping fever
* Enzootic pneumonia

Question 7

What is IBR?

Answer 7

Infectious Bovine Rhinotracheitis
* Common name: Red nose
* Destroys the mucosa, shuts down the muco-ciliary elevator

Question 8

What is BSRV?

Answer 8

Bovine Syncytial Respiratory Virus
* Can cause respiratory disease on its own: Doesn’t need bacterial help

Question 9

What are the signs of respiratory disease?

Answer 9

• Cough
• Nasal discharge: White and milky = allergy; Green, brown = infection
• Rapid breathing
• Epistaxis: Bloody nose

Question 10

When looking at the bovine lung, which is less well oxygenated?

Answer 10

The ventral bovine lung is less well oxygenated than the dorsal lung.

You have more bacterial exposure in the top of the lung (cranial ventral)
- Good indicator of inhaled disease

Question 11

How long does it take for a bovine lung to complete development?

Answer 11

12 months

Question 12

What bacteria is involved in Calf Diptheria?

Answer 12

Caused by:
* Fusobacterium necrophorum
* Histophilus somni

Found in the larynx
- Lymphoid tissue is swollen and necortic

Question 13

What causes Tracheal Stenosis?

Answer 13

• Physical causes; caused by cow pressing down on feeders when eating
• Known as Honker cattle (cattle honk when breathing)

Question 14

What is interstitial pneumona?

Answer 14

When aveloar walls thicken
Usually caused by a Virus or Toxin
* Aerogenous (viral)
* Hematogenous (toxin)

May see impressions of ribs on lungs

Question 15

What are signs of BRSV?

Answer 15

• Necrotizing
• Bronchitits/Bronchiolitis
• Syncytial Cells

Question 16

Suppurative Bronchopneumonia

Answer 16

• See nodules of caseousnecrosis associated with Mycoplasma bovis
• Cold weather disease
• Occurs in the cranial ventral region of the lungs

Question 17

What are extrapulmonary clues of Mycoplasma bovis?

Answer 17

Otitis media
* Gunk in the ear
* Drainage in the ear

Polyarthritis
* Swelling of the joints

Cottage cheese abcesses

Question 18

What bacteria cause Fibrinosuppurative Pneumonia?

Answer 18

• Mannheimia haemolytica
• Histophilus somni
• Pasteurella multocida

Question 19

T/F: Pasteurella is bronchocentric

Answer 19

True

Question 20

What does the presence of “oat cells” indicate?

Answer 20

Mannheimia haemolytica

Question 21

What are signs of Histophilus somni?

Answer 21

• Sleepy cows

somni means sleep