Non-infectious Lower Airway Dz Flashcards
What is equine asthma (heaves, RAO, COPD)
A chronic respiratory disease that causes inflammation in a horse’s airways, making it difficult for them to breathe
What is small airway inflammatory dz (SAID)?
Group of inflammatory conditions of the lower respiratory tract
Cause of impaired performance and interruption of training
What age of horses suffer from equine asthma?
Older horses
What is the age range of horses that suffer form SAID?
Young racehorses
CS of equine asthma
Elevated respiration
Expiratory wheezes
Heave line (hypertrophy of rectus abdominus and EAO muscles)
CS of SAID
Poor racing performance
Cough
Tracheal exudate
What are the predisposing causes of SAID?
Unknown but could be: resp. viruses, bacteria, lung parasites, dust, exercise and elderly
What are the predisposing causes of equine asthma?
Seasonal disorder (summer)
Change in husbandry: hay and housing
Normal % of differential cell count in a bronchoalveolar lavage?
Macros: 40-60%
Lymphos: 40-60%
Neutros: <5%
Mast cells: <2%
Eosins: <1%
lower the volume, higher the neutro count
% differential cell count in a horse with equine asthma and SAID
Neutros: >20%
Mast cells and eosins: >5%
Increased # of eosinophils in a BAL, ddx?
Astham
SAID
Parasitic pulmonary dz
Hypersensitivity pneumonitis
Idiopathic interstitial pneumonia
Sarcoidosis
langerhands cell histcytosis
Advantages of the transendoscopic tracheal wash
Bacteriology
Represents all lung regions
Quick and easy screening
Disadvantagesof the transendoscopic tracheal wash
Less precise reference ranges than BAL
Epistaxis
Advantages of a bronchoalveolar wash
Cytology
Simple to collect
Disadvantages of a bronchoalveolar lavage
Mild coughing, depression, fever
Small area and relies on lung dz being diffuse and homogenous
Can’t take BAL sample without nasopharyngeal contamination
How would a tracheal wash from a horse with equine asthma differ from a horse with bacterial pneumonia?
Asthma: eosinophilia
Pneumonia: neutrophilia without eosinophilia
Tx for equine asthma
Environmental control (steam hay, 2-3w)
Systemic corticosteroids: Prednisolone, dexmethasone, triamicinolone)
Systemic bronchodilators (buscopan, clenbuterol
Inhalation therapy of equine asthma (medication)
Anticholinergic (ipatropium bromide)
B2 agonists (albuterol and clenbuterol)
Mast cell stabilizer (Na cromoglycate)
Corticosteroids(beclomethasone and fluticasone and ciclosenide)
Mucokinesis (acetylcysteine)
Mechanical inhalation therapy
Metered-dose inhalers
Aeromask (with pirbuterol and albuterol)
Environmental management for equine asthma and SAID
Soak hay for 30 minutes to get rid of dust (steamed hay)
Good ventilation
Feed small amounts
Tx protocol for SAID
Outdoors or bed on sand, shavings, peat moss
Pelleted feed or soaked hay
Corticosteroids, systemic, inhaled (ciclosenide)
Bronchodilator drugs
Abx
What is exercise-induced pulmonary hemorrhage?
Blood is present in the airways of the lungs after strenuous physical activity
Causes a horse to stop on the track and finish last
What causes EIPH?
High pulmonary capillary blood pressure during exercise
A. Fib
Blood viscosity, small airway dz, upper airway obstruction, high BP
Pathophysiology of EIPH
Exercise —> pulmonary capillary rupture —> hemorrhage—> inflammation and fibrosis—> reduced lung compliance and angiogenesis
Dx EPIH
Endoscopy (0.2-2 hr post exercise)
Transtracheal wash (hemosiderophages)
Rads (unreliable): ↑ density in the caudodorsal lungs
How do you tx EPIH? Issues with giving this in horses with competition sports?
Furosemide (weight reduction?)
Nasal strips
Correction of layngeal hemiplegia
Aminocaproic acid and conjugated estrogens
