Inflammatory airway disease

Question 1

What is the clinical presentation of inflammatory airway disease?

Answer 1

-young horses
-poor performance & chronic (>3 weeks), occasional coughing

Question 2

What is the diagnostic confirmation of inflammatory airway disease?

Answer 2

-excess tracheobronchial mucus (score </= 2/5 for racehorses & >/= 3/5)
-BALF cytology mild inc in neutrophils, eosinophils &/or metachromatic cells
-C/S of poor performance & chronic (>3 weeks), occasional coughing

Question 3

Horses housed in stables are potentially exposed to high burdens of aerosolized particles, including a variety of organic & inorganic particles including

Answer 3

fungi
molds
endotoxin
beta-D-glucan
ultrafine particles
microorganisms
mite debris
vegetative material
inorganic dusts
noxious gases

Question 4

Besides dust, what environmental conditions can worsen inflammatory airway disease (IAD)?

Answer 4

exposure to cold
dry environments

Question 5

What supplement can improve clinical signs in inflammatory airway disease in horses?

Answer 5

-omega-3 polyunsaturated fatty acids

Question 6

The diagnosis of IAD is based on what?

Answer 6

1. presence of C/S of lower airway disease (poor performance, cough)
2. documentation of lower airway inflammation based on excess mucous on endoscopy, BALF cytology or abnormal lung function
3. exclusion of severe equine asthma (RAO/heaves) as well as infectious & other respiratory diseases

Question 7

What is the mucus scoring system in IAD?

Answer 7

Grade 0= no visible mucus
Grade 1= single to multiple small blobs of mucus
Grade 2= larger but nonconfluent blobs
Grade 3= confluent or stream forming mucus
Grade 4= pool forming mucus
Grade 5= profuse amounts of mucus

Question 8

In comparison with BALF profiles from horses with severe equine asthma show

Answer 8

-mod to severe neutrophilia (>25% cells)
-dec lymphocyte & alveolar macrophage counts

Question 9

What are reference values for normal BALF cytology?

Answer 9

TNCC </= 530 cells/microL
neutrophils </=5%
eosinophils </=1%
metachromatic cells </= 2%

Question 10

What BALF cytology values are consistent with IAD?

Answer 10

> 10% neutrophils
5% mast cells
5% eosinophils

Question 11

Besides severe exercise intolerance & a combination of BALF cytology seen with RAO

Answer 11

neutrophils >25%
tracheal mucus accumulation grade >2/5

Question 12

Why is a Baermann fecal float not reliable in horses for diagnosis of Dictyocaulus arnfeldi?

Answer 12

-parasite does not usually patent in horses

Question 13

What are differentials to consider when diagnosing IAD/RAO?

Answer 13

viral infection
bacterial pneumonia
lungworm infection
EIPH
Neoplasia
Upper airway disease

Question 14

What should be ruled out before using immunosuppressive treatment in IAD?

Answer 14

R/o an active infectious process

Question 15

Why is the use of bronchodilaters in IAD cases?

Answer 15

increased mucociliary clearance obtained after clenbuterol admin may be beneficial in treating IAD

Question 16

Is there any evidence for the use of mucolytics in treatment of IAD?

Answer 16

little evidence for their efficacy in IAD or RAO
– acetylcysteine, bromhexine, ammonium chloride & potassium iodide infusion

Question 17

What are the two main methods for management for IAD?

Answer 17

1. Use “low dust” feedstuff & bedding that generate lower airborne particle concentrations than hay & straw
2. increase elimination of airborne particles & other irritants by improving ventilation in the barn

Question 18

Immersing hay in water reduces exposure to respirable dust by how much?

Answer 18

approximately 60%

Question 19

As far as feeding hay in the management of IAD, what is recommended?

Answer 19

hay fed from a net will result in 4 fold increase exposure to respirable dust in the breathing zone compared to feeding hay on the ground

Question 20

When are peak levels of dust exposure in a barn?

Answer 20

-peak dust exposure occurs during the morning or midday