Bovine Respiratory Disease: Diagnosis

Question 1

Describe the steps in approaching bovine respiratory disease

Answer 1

• Signalment & history
• Examine your patient(s)…how many?
• Examine the environment
• Ancillary testing
• Treatment

Question 2

What are the potential differentials for bovine respiratory disease?

Answer 2

Infections - viruses, bacteria, fungal, parasitic
Allergic
Environment
Combination?

Question 3

What questions should you ask in the history of cattle with respiratory disease?

Answer 3

• Does the signalment give you a clue?
• Does recent history help?
• Is it a group problem or an individual?
• Recent stressors? (“Shipping fever” after transport)
• Wean/disbud/castrate - enzootic pneumonia
• Turned out? When?

Question 4

Stertorous upper respiratory noise indicates which cause of bovine respiratory disease?

Answer 4

Laryngeal pathology, commonly laryngeal chondritis
- May respond to medical therapy (penicillin/anti-inflammatory)
- May require tracheotomy/-ostomy

Question 5

Profuse nosebleeds indicates which cause of bovine respiratory disease?

Answer 5

Vena caval thrombosis…hopeless prognosis
Foreign body (blackthorn prickles)

Question 6

Describe the physical examination of cattle with respiratory disease

Answer 6

• Observe their general appearance… overgrown coat…too cold
• Ear position: depressed/cold (when ears are down)
• Behaviour….lively or depressed? Seeking shelter?
• Coughing ?
• TPR
• Respiratory noise (lung fields AND trachea/URT)
• Respiratory depth (shallow breaths -> pain)

Question 7

When should laboratory samples be taken in cases of respiratory disease in cattle?

Answer 7

Only sample if its going to be useful/affect your decisions/affect the choice of treatment

Question 8

Which normal commensal pathogens should you be aware of when sampling?

Answer 8

Pasteurella and Mannhaemia
URT Mycoplasma can be commensal

Question 9

What individual samples can be taken from cattle with respiratory disease?

Answer 9

• Nasopharyngeal swab…IBR , (RSV, PI3)
• Conjunctival swabs/scrape…IBR, (M.bovis if eyes affected)
• Serology (single/paired)…all; 2-3 weeks apart ; rising titre
• Bronchoalveolar lavage…M.bovis, IBR, RSV, PI3,BVD, Haemophilus, Lungworm
• Faecal sampling re D.viviparous - Baermann technique

Question 10

How is lung scanning used in cattle?

Answer 10

• Prognostic indicator
• Presence of lesions may indicate poor detection
• Between the rib spaces
• Scoring system (Ollivett)

Question 11

Describe the features to assess in the subjective exam of the building

Answer 11

Assess the environment at the level of the animals and breathe it:
…urea? warm air?
… underfoot squelch test
…are you too cold/hot?
…dust in the air? Dusty bedding?
…Does it make you cough?
…Temperature of the bedding

Question 12

Describe the features to assess in the objective exam of the building

Answer 12

1. The stack effect
2. Smoke tests (smoke bomb or metal bucket with straw…dry under damp)
   - The smoke will follow the path of airflow within the building, but as you want to assess airflow when the livestock are in it, you need to perform these tests when it is occupied
   - Hope to see the smoke exit the building

Question 13

What is required for adequate airflow in housing?

Answer 13

Outlet and inlet

Question 14

What are 2 indications of inadequate airflow in housing?

Answer 14

Tiger stripes
Cobwebs

Question 15

What are 2 reasons for a lack of stack effect?

Answer 15

No outlet or building too high
Insufficient biomass (bodies! Little calves !)

Question 16

What is the stack effect?

Answer 16

• Animals breath out warm air which rises and escapes through the highest point of the building (outlet)
• This creates negative pressure within the building which draws fresh air back in through the inlets