Equine: airway dysfunction & disease Flashcards
Signs of URT disease
- unilateral nasal discharge (cranial to nasal septum)
- dull areas when sinuses are percussed
- audible respiratory noise localized to the URT
Signs of mid-lower respiratory tract disease
- increased RE and RR at rest
- ausculable abnormal respiratory sounds localized to thorax
- bilateral nasal discharge
- pleurodynia (pleural pain)
Describe Strangles and this endoscopic finding.
retropharyngeal lymph node ruptures in medial chamber of guttural pouch; Strep equi ss equi organisms can remain in the pouch long after disease resolves and thus horses can serve as carriers
image: guttural pouch empyema
Describe Guttural Pouch Mycosis and this endoscopic finding.
Aspergillus fumigatus grows on top/penetrates internal carotid a. within guttural pouch -> epistaxis (can be severe/horse can bleed out)
Common clinical signs with Left Laryngeal Hemiplagia
noise on inspiration, can worsen with exercise
Function problem of the upper airway
What are two common diseases that affect the Mid-lower RT of horses?
Infectious: Equine influenza
Non-infectious: Equine asthma
What is the typical breathing pattern of equine asthma when it becomes severe?
Abdominal press with nostril flare
nostril flare b/c they are trying to decrease airflow resistance/increase their Vt
What is the indication if you visulaize a lot of tracheal mucus during an endoscopic exam?
directly proportional to amt. of inflammation present -> TTW cytology should also show neutrophilia
Neut. morphology is not suggestive of infection. –> dx = equine asthma
75% neutrophils (normal is < 15%)
Characteristics of equine asthma
- recurrent, seasonal, chronic dz
- middle-aged to older horses
- progresses with time if not properly managed; no cure, but remission can occur:
- mild = occasional cough, moderate = exercise intol. + more frequent cough, severe = respiratory distress @ rest, nostril flare and heave line, wt loss
Heave Line: The abdominal muscles must work hard to assist with exhaling, and overdevelopment of these muscles produces a line along both sides of the abdomen known as a “heave line.” Wheezing may be caused by airflow through narrowed airways, and is most obvious when the horse is exhaling.
Causes of equine asthma
- exposure to environmental debris (mold, fungus)
- feeding rounde bale hay (when it rains, the center of the hay gets moldy and concentrated with endotoxins, ammonia, etc.)
What is the purpose of treating equine asthma with corticosteroids and bronchodilators?
corticosteroids: reduce airway inflammation
bronchodilatiors: relax airways
corticosteroids: inhaled (human meds) vs systemic (dexamethasone and prednisolone) – start with highest doese and slowly reduce to find LED
bronchodilators: albuterol, clenbuterol (beta-2 agonists) vs Ipratropium (M2-agonist)
Young race horse presents for cough and poor performance. Physical exam in unremarkable, but bronchoalveolar fluid sample cytology shows neutrophilia w/out evidence of infection. What is your diagnosis and how would you treat?
Inflammatory Airway Disease (IAD)
- tx = short-course corticosteroids
- early form of asthma
What disease do high performance horses often develop? Pathogenesis and tx?
Exercise-Induced Pulmonary Hemorrhage
- during times of high exercise, capillary hydrostatic pressure increases over 100mmHg -> blood vessels rupture into alveoli
- with repeated episodes, the amt. of blood that ruputres out escalates
- tx = lasix therapy short-term, rest long-term
What aspects of the history justify an infectious MLRT diagnosis in horses?
- fever (usually suggests viral)
- recent exposure to other/new horses, who also show signs of disease
What is Horsemen’s rule for equine pneumonia recovery?
- temp daily until resolution
- rest one week for every day horse had fever
Findings on thoracic u/s?
circle = abscess -> if multiple abscesses found throughout the lung, strongly indicative of Rhodococcus equi pneumonia
