Rquine Asthma

Question 1

What is the neutrophil % for mild asthma

Answer 1

10-25% or 5% eosinophils

Question 2

What % neutrophils for severe equine asthma

Answer 2

> 25%

Question 3

Treatment for mild asthma

Answer 3

Immune modulation
Omega 3 supplementation

Question 4

Therapy for m/sEA

Answer 4

Glucocorticoids
Bronchodilators

Question 5

Diagnosis of equine asthma

Answer 5

History/physical exam
Auscultation
Rebreathing bag
Endoscopy
BAL

Question 6

Phenotypes of mEA on BAL

Answer 6

Neutrophils >10%
Mastocytes >5%
Eosinophils>5%

Question 7

sEA phenotype on BAL

Answer 7

Neutrophils>25%
In remission 10-20%
Degenerated with vacuolisation

Question 8

What tissue remodeling occurs in equine asthma

Answer 8

Increased smooth muscle mass
Peribronchial fibrosis
Epithelial hyperplasia
Bronchiectasis

Question 9

Pathophysiology of asthma

Answer 9

Hyper-responsive airway
Bronchospasm
Inflammation
Mucous accumulation

Question 10

Aetiology of asthma

Answer 10

Non-allergenic inflammation
Genetic
Hypersensitivity reaction
Strong association with environmental particles

Question 11

Difference between presentation of aEA and sEA

Answer 11

sEA > 7, mEA any age
CS
- sEA - performance reduced, resting dyspnoea, frequent cough
- mEA - no resting dyspnoea, occasional cough, >3weeks length
Progressions
- mEA - spontaneous improvement or drug improvement with no reoccurrence
- sEA reoccurrence requiring long term treatment

Question 12

Tracheal wash procedure

Answer 12

30-50ml sterile saline installed where trachea is parallel to ground
Good screening, represents both lungs
Preferred c and s method
Accuracy for mEA unknown

Question 13

BAL procedure

Answer 13

~250ml sterile saline into one lung
Good for diffuse pathology
Specific
Preferred for EA diagnosis

Question 14

Cytology on tracheal samples

Answer 14

Macrophages most abundant, lymphocytes second
Neutrophils most common abnormalities
Eosinophils should be < 1%

Question 15

Glucocorticoids

Answer 15

High efficacy - extensively used
Impacts on lung function, airway inflammation, bronchial remodelling but does have adverse effects

Question 16

Systemic Glucocorticoids

Answer 16

Prednisolone - poor bioavailability
Dexamethasone - superior, lasts longer
Isoflupredone - causes hypokalemia

Question 17

Treatment in acute sEA

Answer 17

IV dexamethasone followed by oral dexamethasone
Then followed by inhaled Glucocorticoids - beclomethasone dipronpropriate
- fluticasone
- ciclesonide - new prodrug, does not effect cortisol levels

Question 18

Corticosteroids for mEA

Answer 18

Oral dexamethasone or Prednisolone
+ Inhaled Glucocorticoids
- beclomethasone
- fluticasone
(Tapered over 4 weeks)

Question 19

Bronchodilators

Answer 19

Alongside glucocorticoids
Beta-adrenergic (clembuterol, Albuterol, salbutamol)
Parasympatholytics (ipratropium)

Question 20

Other drugs for asthma

Answer 20

Interferon-alpha - can show better treatment response/decreased relapse rate
Cromoglicate - mast cell mediated
Omega 3 fatty acids

Question 21

Adverse effects of drugs

Answer 21

Glucocorticoids
- adrenal suppression/adrenal gland atrophy)
- immune suppression
- laminitis
Systemic beta-adrenergic bronchodilators
- cardiovascular remodelling
- tachyphylaxis

Question 22

Regulations

Answer 22

Check with BHA for drug withdrawal times for competition

Question 23

How can you reduce environmental dust

Answer 23

Keep outside
Free of urine/manure
Hay cubes/pelleted feed
Soaked/steamed hay/haylage
Clean cool environment
Cardboard/dust free shavings
Feed from the ground

Question 24

What distance from the nose is the breathing zone

Answer 24

30cm

Question 25

How long does it take to clinical remission with changes

Answer 25

4-8weeks

Question 26

Extra suggestions to reduce dust

Answer 26

Sprinkle with water before sweeping
Turn bedding banks every day
Take horses outside whilst cleaning
No indoor blowers
Avoid hay storage near horses