Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

EQUINE > 8.2.2: Equine asthma > Flashcards

8.2.2: Equine asthma Flashcards

1
Q

How do we categorise equine asthma?

A
  • Mild-moderate equine asthma (IAD)
  • Severe equine asthma (RAO)

Equine asthma was formerly known as broken wind, heaves, chronic obstructive pulmonary disease (COPD), recurrent airway obstruction (RAO), inflammatiry airway disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

True/false: in mild-moderate equine asthma, there are subtle clinical signs at rest.

A

False
Only in severe equine asthma are there signs at rest.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

1

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

2

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

3

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

4

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

5

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

6

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

7

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

8

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

9

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

10

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

11

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

12

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

13

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

On cytology for severe asthma, neutrophils make up what % of the TNCC?

A

25%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

On cytology for mild-moderate asthma, neutrophils make up what percentage of the TNCC?

A

10-25%
We also see increased mast cells in mild-moderate asthma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

True/false: all horses which have mild asthma will eventually develop into those with severe asthma.

A

False
Not all horses will mild form show progression to severe form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Aetiology of equine asthma

A
  • Strong association with environment and feeding
  • Mechanisms are poorly understood
  • It is a non-allergic inflammatory response e.g. to endotoxins, moulds, noxious gases; but there can also be an allergic reaction component that involves Type I and Type III hypersensitivity
  • There seems to be a familial risk for moderate and severe equine asthma so some suggest genetic testing should be performed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How can environment and feeding impact equine asthma?

A
  • Airborne respiratory dust (ARD) causes and exacerbates the disease
  • Some particles in the breathing zone and stable zone, if small enough (<5µm) will make it into the lower airways but not back out - these particles e.g. moulds and fungi trigger disease
  • There is a lower concentration of these in steamed hay
  • Hay dust exacerbates asthma - even a horse in remission can be affected
  • Higher concentrations from nets (4x higher respirable dust)
  • The breathing zone is 30cm around the horse’s nose
21
Q

Which organisms may play a role in the hypersensitivity allergic reactions that may come with asthma?

A
  • Faenia rectivirgula
  • Aspergillus fumigatus
  • Thermoactivenomyces vulgaris
22
Q

Pathophysiology of equine asthma

A
  • Airway hyper-responsiveness
  • Bronchospasm
  • Inflammation
  • Mucus accumulation
  • Tissue remodelling
23
Q

Discuss how bronchospasm occurs in equine asthma

A
  • Occurs secondary to inflammation
  • Bronchodilators are effective
24
Q

Discuss the signs of inflammation we can see on cytology of the horse with equine asthma

A
  • Airway neutrophilia
  • Activation of macrophages occurs
25
Q

Describe how mucus accumulation plays a role in equine asthma

A
  • Consistent finding in equine asthma
  • Perhaps associated with the neutrophilia but not sure
  • Long persistence (even during remission)
  • Exacerbations increase viscoelasticity (and just generally will increase the production of mucus by goblet cells)
26
Q

Describe how tissue remodelling plays a role in equine asthma

A
  • Increased smooth muscle mass -> increased contraction force
  • Peribronchial fibrosis
  • Epithelial hyperplasia
  • Bronchiectasis: inflow of air into some segments of lower airways, and outflow impaired by these issues. This means there is too much air in the alveoli -> they burst and form larger balloon-like structures
27
Q

Which small particles (<5µm) can cause disease?

A
  • Moulds and fungi
  • Pollen
  • Endotoxins
  • Chemicals: ammonia, smoke, exhaust fumes
28
Q

Diagnosis of equine asthma

A
  • History
  • Physical exam
  • Auscultation - use a rebreathing bag
  • Endoscopy
29
Q

How can a rebreathing bag be used to help diagnose equine asthma?

A
  • Place bag around the horse’s muzzle. This will increase CO2, and thereby increase depth ad effort of respiration
  • This makes it easier to hear respiratory sounds on auscultation
  • Check for tolerance, cough, recovery
  • This is especially important for horses with mEA -> they will not tolerate the bag for very long
  • May hear wheezes, crackles, tracheal rattles

⚠️Do not use a rebreathing bag if the horse is in respiratory distress⚠️

30
Q

How can endoscopy be helpful in investigation of equine asthma?

A
  • Rule out upper airway disease
  • Can see tracheal mucus
  • Perform 1hr post exercise
  • Make sure to visualise the carina
31
Q

Who has equine asthma?

A

Horse 1

32
Q

1

A
33
Q

2

A
34
Q

3

A
35
Q

4

A
36
Q

SPAOPA

A

Summer pasture-associated obstructive pulmonary disease

37
Q

What broad classes of drugs can be used to treat horses with asthma?

A

Horses with mEA only may benefit from:
* Immune modulation (interferon-alpha)
* Omega-3 supplementation

Horses with mEA and sEA may benefit from:
* Glucocorticoids
* Bronchodilators

38
Q

Why are glucocorticoids used to treat equine asthma?

A
  • High efficacy and extensive use
  • Impact on lung function, airway inflammation, bronchial remodelling
  • Side effects include: adrenal suppression, adrenal gland atrophy, immune suppression, laminitis
  • Inhaled therapy may be preferable to systemic for long-term treatment
39
Q

How could you use glucocorticoids to treat the horse with acute sEA?

A
  • IV dexamethasone (0.04-0.1mg/kg SID)
  • Followed by PO dexamethasone 0.05 mg/kg OR prednisolone 1mg/kg SID - give until respiratory effort and nasal discharge resolve
  • Then follow with inhaled glucocorticoids: ideally fluticasone 2000µg BID, otherwise Beclomethasone diproprionate 3750µg BID
40
Q

Characteristics of ciclesonide for treatment of sEA

A

Ciclesonide
* Glucocorticoid
* Pro-drug
* Does not affect cortisol
* Dose: 8 activations BID for 5 days, then 12 activations SID

41
Q

Glucocorticoid treatment protocol for mEA

A
  • Start PO dexamethasone 0.05mg/kg OR prednisolone 1mg/kg SID - for 4 weeks
  • Follow this with inhaled glucocorticoids:
  • Initially fluticasone 2000µg BID, tapered over 4 weeks to 1000µg every 48hrs
  • Can then use Beclomethasone diproprionate 500-1500µg BID
42
Q

What bronchodilators are available for treatment of equine asthma and how should you use them?

A

Use bronchodilators alongside glucocorticoids
* There are beta-adrenergic and parasympatholytic options

Beta-adrenergic
* e.g. Clenbuterol, albuterol, salbutamol
* Give inhaled for mEA, systemic for sEA
* Systemic: Clenbuterol PO starting at 0.8µg/kg BID then increasing to 3.2µg/kg BID; clenbuterol IV not recommended due to side effects
* Inhaled: salmeterol (0.5-1µg/kg q6hrs) or albuterol (0.8-2µg/kg q1-6hrs)

Parasympatholytic
* = ipratropium bromide (0.4-0.8µg/kg q4hrs)

43
Q

How could you use interferon-alpha in the treatment of equine asthma?

A
  • 50-150 U / horse/ day
  • May see positive response to treatment and decreased relapse rate
  • However practical experience is mixed
44
Q

How could cromoglicate be used in treatment of equine asthma?

A
  • Used in mast-cell mediated mEA
45
Q

How could omega-3 fatty acids be used in treatment of equine asthma?

A
  • 1.5-3g DHA for both mEA and sEA
46
Q

Side effects of glucocorticoids

A
  • Adrenal suppression
  • Adrenal gland atrophy
  • Immune suppression
  • Laminitis
47
Q

Systemic beta-adrenergic bronchodilators

A
  • Cardiovascular remodelling
  • Tachyphylaxis
48
Q

What must you take into account and warn the owner about if their horse is on long term treatment for equine asthma? Where is a good place to look for the required information?

A
  • Each drug and delivery method has a detection time
  • The treatment should be discontinued before that time
  • Times may vary according to pathology and other factors
  • These times change so should be rechecked regularly (see BHA website or individual competition information)

EQUINE (59 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions