Respiratory

Question 1

T or F:
Bilateral nasal discharge can be associated to upper OR lower respiratory disease.

Answer 1

True.

Question 2

T or F:
Cough is associated with upper and lower respiratory disease.

Answer 2

True.

Question 3

T or F:
Unilateral nasal discharge is associated with upper and lower respiratory disease.

Answer 3

False!
*unilateral discharge is usually associated with upper respiratory disease…
—> anatomic location that delineates: CAUDAL edge of the nasal septum*

{Rostral to this: unilateral—>UR;
Caudal to this: bilateral—>LW}

Question 4

T or F:
A horse can manifest a neutrophilic leukocytosis and hyperfibrinogenemia with either upper OR lower respiratory disease.

Answer 4

True; indicates infectious disease (irrespective of location)

Question 5

2nd most common clinical sign of guttural pouch mycosis?

Answer 5

Dysphagia!

Question 6

First most common clinical sign of GPM?

Answer 6

Epistaxis!

Question 7

What specific structures are usually affected in GPM?

Answer 7

Internal carotid a. (located in the medial pouch);

Maxillary a. (Located in the lateral pouch) *these can be combinations*

Question 8

If we are suspecting ethmoid hematoma, but cannot confirm on endoscopy, what should we do?

Answer 8

• *Run skull radiographs**;
• Ethmoid hematomas can be in deeper tissue (not accessible by scope)*

Question 9

How do we medically treat ethmoid hematomas?

Answer 9

Inject with formalin

*can eat into cribiform plate, so if the hematoma has breached, we do NOT want to inject with formalin, because it will go to the brain*

Question 10

What is the most common cause of epistaxis in the horse?

Answer 10

Trauma!

Question 11

What’s the classic signalment for an ethmoid hematoma?

Answer 11

Older,
male,
warm-blood (thoroughbred) horses

Question 12

Why do we think GPM lesions are usually over arteries?

Answer 12

Attracted to oxygen tension…

Question 13

Why do GPM (or empyema) horses present with dysphagia?

Answer 13

Nerves, most notably the Vagus (with branches, Pharyngeal especially)
… comes off near the middle of the pouch, run at the back of the pouch and run on the floor of the pouch
—> they get a dorsally displaced soft palate
(dysphagia is associated with this resulting dysfunction)

Question 14

How do we diagnose IAD?

Answer 14

**BAL**…and cytological evaluation revealing:

Neutrophilia >10%;

Mast cells >5%;

And Eosinophils >5% using 250mL saline

Question 15

What is the pathophysiology behind airway thickening in RAO?

Answer 15

Exposure to particulates —>Peribronchial infiltrates and epithelial metaplasia

Question 16

How would we diagnose RAO?

Answer 16

Cytological analysis revealing:
suppurative nonseptic inflammation
—> neutrophilia >25%,
…decrease lymphocyte and alveolar macrophages —> tracheal mucus accumulation

Question 17

How do we treat RAO?

Answer 17

Decrease env’t challenges (need this element for the anti-inflammatories to be effective) Bronchodilator Anti-inflammatories

Question 18

How can we manage the environment in treating RAO?

Answer 18

Good ventilation in housing,
Adequate bedding,
Minimized dust,
Pellet feed, hay cubes, soak hay in water

Question 19

What are the 3 main classes of bronchodilators that we should use in treating RAO?

Answer 19

Anticholinergics,
Beta-2 agonists,
Phosphodiesterase inhibitors

Question 20

How do beta-2 adrenergic agonists relax smooth muscle?

Answer 20

By increasing the intracellular levels of cAMP

Question 21

If you’re treating a horse with bronchodilator and steroids, which one should be administered first?

Answer 21

Bronchodilator first;
To improve glucocorticoid deposition

Question 22

What is the normal Pulmonary Arterial Pressure (PAP) at rest vs. during exercise?

Answer 22

at rest (pretty much the same across all species): 25-30 mmHg

​exercise: 125 mmHg

Question 23

What is the bronchial system MABP at rest vs.exercise?

Answer 23

Rest: 100 mmHg

​Exercise: 220 mmHg

Question 24

What is the bronchial system pressure reflective of?

Answer 24

The SYSTEMIC circulation (high-side of system)

Question 25

How do we begin the physical exam evaluation of respiratory disease?

Answer 25

start with **differential airflow**: - evaluate sinuses - evaluate/palpate larynx and trachea THEN go into auscultation

Question 26

Where are we located? Does this look normal?

Answer 26

**Distal nasopharynx** NO because we can’t see the epiglottis; *think dorsally displaced soft palate*

Question 27

Where are we located?

Answer 27

Distal trachea

Question 28

What is this structure?

Answer 28

Ethmoid turbinate *left side*

Question 29

Which *_compartment_* of the *guttural pouch* do main structures go thru? | (internal carotid a, nerves)

Answer 29

**Medial** (~200mL) *vs lateral ~100mL* the 2 compartments are separated by the *_stylohyoid_*

Question 30

If we are suspecting ***infectious, focal*** disease, what procedure is indicated?

Answer 30

TTW!

Question 31

If we are suspecting ***non-infectious, diffuse*** disease, what procedure is indicated?

Answer 31

BAL!

Question 32

What is the anatomic location where the distinction is made as to whether the horse will have unilateral vs. bilateral discharge?

Answer 32

**Caudal edge of the nasal septum** *rostral to the caudal edge of nasal septum? —\> should be UNILATERAL* *caudal to the caudal edge of nasal septum? —\> should be BILATERAL*

Question 33

T or F: A horse can manifest a **neutrophilic** **leukocytosis** and **hyperfibrinogenemia** with either *upper or lower* respiratory disease.

Answer 33

Trueeee

Question 34

What is the location of the lesion?

Answer 34

**Medial** compartment of **RIGHT** guttural pouch

Question 35

How is the **discharge** different in ethmoid hematomas from GPM?

Answer 35

EH: intermittent/purulent GPM: mucoid type, possible between episodes

Question 36

Older male horses are more likely to succumb to \_\_\_\_\_\_, whereas younger horses are more likely to succumb to \_\_\_\_\_\_.

Answer 36

Older male horses: Ethmoid hematoma younger: GPM

Question 37

What is the normal respiratory rate for a horse anyhow?

Answer 37

8-20 bpm \*foal: 12-24\*

Question 38

What are 2 terms we use to describe abnormal lung sounds?

Answer 38

1. **Crackles**: *low-pitched, non-musical sounds - short, explosive sounds* 2. **Wheezes**: *high-pitched, musical sounds - long, musical sound associated w narrowing of airways generated by oscillation of bronchial and bronchiolar walls*

Question 39

On pulmonary evaluation via ultrasonography, how would an atalectic lung differ from a consolidated one?

Answer 39

**Atalectic**: very sharp, concave/convex borders with reduced volume ​**Consolidated**: rounded borders - two convex borders meeting

Question 40

In progressive ethmoid hematoma, is the epistaxis *_typically_* unilateral or bilateral?

Answer 40

Unilateral!

Question 41

What is the signalment for progressive ethmoid hematoma?

Answer 41

4 yrs + thoroughbred, warmbloods, Arabians

Question 42

What would confirm our diagnosis of EIPH on endoscopy?

Answer 42

Direct observation of blood in **tracheobronchial tree**

Question 43

What is the reasoning behind treating EIPH with furosemide?

Answer 43

Profound diuresis—\>volume reduction—\>decreased blood pressure in lung (*thus diminishing work and pressures) \** also bronchodilation\*