Tracheobronchial Disease

Question 1

EIPH 0-4 grading scale

Answer 1

Grade 0: no blood detected in the pharynx, larynx, trachea, or mainstem bronchi.

Grade 1: presence of one or more flecks of blood or ≤2 short (less than 1/4 length of the trachea) & narrow (10% of the tracheal surface area) streams of blood in the trachea or mainstem bronchi visible from the tracheal bifurcation.

Grade 2: 1 long stream of blood (more than 1/2the length of the trachea) or more than two short streams of blood occupying ≤33% tracheal circumference.

Grade 3: multiple, distinct streams of blood, covering >33% of tracheal circumference, with no blood pooling at the thoracic inlet.

Grade 4: multiple, coalescing streams of blood covering 90% of the tracheal surface with blood pooling at the thoracic inlet.

Some scales add grade 5 to include grade 4 + evidence of epistaxis

Question 2

Key findings of Crispe et al (EVJ 2019) WRT EIPH severity over time in TB racehorses

Answer 2

Key Points

1. EIPH severity can vary between races
2. Increasing no of days between races for horses ≥2 at the first observation was assoc with decreased EIPH severity at next exam - likely dt time for inflamm to settle
3. Colder ambient temp assoc with higher EIPH grade (in low grade horses at first exam, most likely to deteriorate with low ambient temps) - likely dt cold induced airway inflammation and pulmonory hypertension in other spp
4. Reduction in weight carried also assoc w ↑ing grade in prev ↓grade horses; likely reflects increase in class? (Racing intensity can affect EIPH)

Question 3

What were the main findings of Bonomo 2019 (TVJ) WRT EIPH in SJ horses?

Answer 3

• EIPH associated with higher level exercise - correlations between higher heart and respiratory rates with endoscopic tracheal blood scores suggest that jumping horses performing at higher levels of competition experience higher intravascular pressures than those performing at lower levels
• EIPH was more frequent in the high (66.7%; 1.30-1.50m) vs low (50%; 1.00-1.10m) group and more severe grades (no G4-5 EIPH in the low group) - see table

Question 4

Endoscopic grading of tracheal collapse

Answer 4