Clinical examination of respiratory diseases in horses

1. Dr. Ajith Y. MVSc PhD
Assistant Professor
Teaching Veterinary Clinical Complex, COVAS, Mannuthy
Department of Veterinary Clinical Medicine, Ethics and Jurisprudence
Kerala Veterinary andAnimal Sciences University, Pookode

3. • Equine Respiratory Medicine and Surgery 1st Edn by McGorum
B., Robinson N.E., Schumacher J., Dixon P. (2006) Elsevier/Saunders.
• Equine Respiratory Diseases by Rush B., Mair T. (2004) Wiley.
• Equine Internal Medicine 4th Edn by Reed S., Bayly W., Sellon D. (2017)
Elsevier/Saunders.
• Equine Sports Medicine and Surgery 2nd Edn by Hinchcliff K.W., Kaneps
A.J., Geor R.J. (2013) Elsevier/Saunders.
• Equine Neonatal Medicine and Surgery 1st Edn by Knottenbelt D., Holdstock
N., Madigan J. (2004) Elsevier/Saunders.
• Saunders Equine Formulary 2nd Edn by Knottenbelt D., Malalana F.
• Journal of Equine Veterinary Science Elsevier (Impact Factor: 1.100)
• Equine Veterinary Journal Wiley Online (Impact Factor: 2.477)
• Veterinary Clinics of North America: Equine Practice Elsevier (IF: 0.770)

4. • Respiratory health is important in the athletic
performance of horses (Examine during rest and exercise).
• Even a mild disease affecting lung capacity may make
the animal useless.
• Anatomical and Physiological protective mechanisms
- Turbinates & mucus covered epithelium (filters upto 5 µm)
- Mucus and Mucosal IgA secretion is more
- Cough reflex, Ciliated epithelium helps in swallowing
- Large soft palate – ‘Mouth is for eating, not for respiration’

5. • More immune cells (esp macrophages) and highly
vascular - Alveolar phagocytosis
• Shock organ of equine – Lungs and intestines
(Dog – Liver and GI tract; Ruminants, Cats – Lungs; Human - Heart)
• LRT infections mainly due to flare up of normal
commensals present in URT
• Stress… (transport, housing and ventilation)
• Obstruction or trauma or lack of rest

8. • In young, Congenital & Developmental disorders
– Choanal atresia, Cysts, lung hypoplasia, hyperkalemic
periodic paralysis (skeletal Na+ channels affected)
• Ventilation and housing details
• Aberrant /Recent changes and STRESS
• Exercise Induced Pulmonary Hemorrhage (EIPH)
• Climate/Weather….Humidity and Pollen grains

9. • Respiratory Rate (8-12 breaths pm)
• Efforts/Difficulty (Inspiratory-Upper/Expiratory-Lower)
• Pattern (abdominal/thoracic)
• Extended head and neck, Nasal flare
• Stertor (low pitch) vs Stridor (High pitch)
• Location - Snoring, Roaring, Wheezes, Crackles
• Nasal discharges (Unilateral/Bilateral)
• Type of discharges (Serous, Mucous, Serosanguinous,
Purulent, Epistaxis, Hemaptysis in horse?)

10. • Palpation, Percussion - pleural effusions, Auscultation
Maxillary sinusitis (Unilateral swelling)

11. • GROSS & Microscopic evaluation of Aspirate/Smear-
Cytology/Bacteriology/Mycology/FNAC (Maxillary swelling)
• Thoraco/Pleurocentesis and Thoracoscopy
• Lung Biopsy (Miliary TB, Neoplasms, Fibrosis)
• Tracheobroncheal Aspiration – Invasive technique
• Broncho Alveolar Lavage (BAL) (through nasal)
• Radiography & Thoracic USG (difficult due to air)
• Culture (bacterial, fungal, viral) and Sensitivity testing
• Endoscopy- Rhinoscopy, Bronchoscopy, Laryngoscopy

12. • Arterial Blood Gas Analysis
• Tidal Volume, Inspiratory volume, Expiratory Volume,
Frequency

13. • VIRUS – Equine Influenza Virus (EIV), Equine Herpes
Virus (EHV 1-5), Equine Rhino Virus, Equine Adeno Virus,
African Horse Sickness (Dunkop)
• BACTERIA – Streptococcus equi , Rhodococcus equi,
Mycoplasma sp., Burkholderia mallei (granuloma),
Staphylococcus sp.
• FUNGUS – Aspergillus sp. (chronic)
• PARASITES – Myiasis by Habronema muscae, Draschia
megastoma
• NEOPLASMS – Sinus tumours, Metastatic in lungs
EHV 5 causes Equine Multinodular Pulmonary Fibrosis

14. • Mostly unilateral, Bilateral in viral infections
• Treatment: Debridement, Draining and flushing, local antiseptic,
oral/systemic antibiotics and antifungals, surgical ostectomy

15. • Etiology similar to sinusitis; GP empyema, GP mycosis
• Nasal discharge, submandibular lymphadenopathy, Inspiratory
sounds, Dysphagia, Neuropathy

16. • Antibiotic + Surgical drainage
• CHONDROIDS – Inspissated pus with cottage cheese like appearance
in guttural pouch

17. • Purpura hemorrhagica - Aseptic necrotizing vasculitis (Type III)
characterized by edema and petechial or ecchymotic hemorrhage.
• Other signs of Sinusitis, Pneumonia, Septicemia

18. • Left Recurrent Laryngeal Nerve is more affected (more length)
• ROARING
• CORDECTOMY & VENTRICULECTOMY or Prosthetic laryngeoplasty

19. • It is the non-infectious condition causing breathing difficulty due
to narrow airways and excess mucuos due to hyper sensitive/
uncontrolled inflammatory response.
B) Heaves / Equine Recurrent
Airway Obstruction
- Severe equine asthma
- In Adult animals
- Like COPD in human
A) Inflammatory Airway Disease
- Mild to moderate equine
asthma
- In Young animals

20. i) Antibiotics/ Chemotherapeutic agents/Antiparasitic/Antifungal
ii) Antiinflammatory
- NSAIDs may not be enough
- Corticosteroids (Hydrocortisone, Prednisolone, Dexamethasone)
- Inhaled Corticosteroids (Beclomethasone, Budesonide, Fluticazone)
aerosolized
iii) Antihistamines
iv) Bronchodialators
- Beta 2 – adrenergic agonists (Salbutamol, Clenbuterol)
- Methyl Xanthines
- Parasympatholytics (Ipatropium bromide)
v) Mucolytics/Expectorant (Commercial preparations, Ammo Chlor, NAC)

21. 1. Define eg- COPD, EIPH, Roaring, Chondroids…..
2. Specific etiological agents – eg: Strangles – S. equi. Left recurrent LN
3. Short Notes and Essays - eg: Heaves, Guttural pouch empyema

22. ajithy@kvasu.ac.in
ajithy123456789@gmail.com
+91 8891981301 (WhatsApp)