Equine Respiratory Diseases

Dr Rush gained her DVM degree from The Ohio State University in 1989. She completed her internship training at North Carolina State University in 1990, and her internal medicine residency training at The Ohio State University in 1993. She has been awarded the 1996 and 2003 Carl J. Norden Distinguished Teacher Award and the 2002 Pfizer Award for Research Excellence at Kansas State University.Dr. Rush's research interest is equine respiratory disease, particularly respiratory physiology, immunology, and aerosol drug therapy. Her clinical interest is in equine respiratory, neurologic, and immune-mediated disease.

"The text is relatively comprehensibve in describing diagnostic, medical and surgical procedures""The general nature of the contents and its user friendly format will lend itself to equine practitioners, veterinary students and equine veterinary nurses alike." Equine Veterinary Journal, 2005

• About the Authors xvIntroduction xviiSection I: Examination of the Equine Respiratory Tract 1Chapter 1: Examination of the Upper Respiratory Tract 3Chapter 2: Examination of the Lower Respiratory Tract 7Section II: Noncontagious Diseases of the Upper Respiratory Tract 11Chapter 3: Diseases Causing Airway Obstruction in the Horse 13Pathophysiology 13Respiration and Locomotion 14Respiratory Noise 14Diagnosis of Airway Obstructions 15History 15Palpation tests 15Endoscopy at rest 15Radiographic examination 16Exercise tests 16Treadmill endoscopy 16Spectrum analysis of respiratory sounds 17Further Reading 17Chapter 4: The Nasal Cavity and Paranasal Sinuses 19Anatomy 19Nasal cavity 19Paranasal sinuses 20Function 23Examination of the Nasal Cavity and Paranasal Sinuses 23Common presenting signs 23History 23Physical examination 24Endoscopic examination 24Radiographic examination 25Computed tomography (CT) and magnetic resonance imaging (MRI) 25Nuclear scintigraphy 27Percutaneous centesis 27Surgical exploration and biopsy 27Treatment Objectives in Nasal and Sinus Disease 27Medical Management 28Trephination of the Paranasal Sinuses 28Bone Flap Surgery 29Further Reading 31Chapter 5: Congenital and Developmental Malformations of the Nasal Cavity 33Wry Nose 33Nasal Septal Deviation 34Choanal Atresia/Stenosis 35Further Reading 35Chapter 6: Diseases Affecting the Nostrils (External Nares) 37Hypertrophy of Alar Folds/Redundant Alar Folds 37Epidermal Inclusion Cyst (“Atheroma”) of the False Nostril 38Lacerations and Wounds of the Nostrils 39Alar Cartilage Necrosis 39Paralysis of the Nostrils 39Further Reading 39Chapter 7: Diseases of the Nasal Cavity and Paranasal Sinuses 41Primary and Secondary Sinusitis and Sinus Empyema 41Clinical signs 42Diagnosis 42Treatment 43Prognosis 44Progressive Ethmoidal Hematoma 44Clinical signs 45Diagnosis 45Treatment 47Prognosis 48Paranasal Sinus Cysts 48Clinical signs 48Diagnosis 48Treatment 49Prognosis 49Fungal Rhinitis and Sinusitis 49Cryptococcosis 49Rhinosporidiosis 49Phycomycosis 50Coccidioidomycosis 50Aspergillosis 50Sinus and Nasal Neoplasia and Polyps 50Clinical signs 51Diagnosis 51Treatment 51Prognosis 51Amyloidosis 52Conchal Necrosis and Metaplasia 52Intranasal Foreign Bodies 52Facial and Sinus Trauma 53Subcutaneous Emphysema 53Further Reading 54Chapter 8: The Guttural Pouches 57Anatomy and Function of the Guttural Pouches 57Signs of Guttural Pouch Diseases 59Examination of the Guttural Pouches 59Palpation 59Endoscopic examination 60Radiographic examination 61Cytology 62Other diagnostic imaging techniques 62Surgical approaches to the guttural pouches 62Hyovertebrotomy 62Viborg’s triangle 63Paralaryngeal (Whitehouse) approach 63Modified Whitehouse approach 64Topical Treatment of the Guttural Pouches 64Guttural Pouch Tympany 64Clinical signs and diagnosis 65Treatment 66Prognosis 67Diverticulitis of the Guttural Pouch 67Strangles 68Chronic gutteral pouch empyema and chondroids 68Chronic diverticulitis 71Guttural Pouch Mycosis 72Clinical signs 74Diagnosis 74Treatment 75Prognosis 77Other Disorders of the Guttural Pouches 78Foreign bodies 78Neoplasia 78Further Reading 79Chapter 9: The Pharynx 81Anatomy 81Dorsal Displacement of the Soft Palate 82Extrinsic factors 83Intrinsic factors 84Clinical signs 85Diagnosis 85Treatment 86Conservative measures and medical treatments 86Surgical treatments 87Staphylectomy 87Strap muscle resection 87Llewellyn procedure—Sternothyroid muscle resection and staphylectomy 88Epiglottic augmentation 88Tension palatoplasty 88Laryngeal tie-forward 89Prognosis 89Pharyngeal Lymphoid Hyperplasia 89Clinical signs 90Diagnosis 91Treatment 91Nasopharyngeal Cicatrices 92Clinical signs 92Diagnosis 92Treatment 92Cleft Palate (Palatoschisis) 93Clinical signs 94Diagnosis 95Treatment 95Prognosis 95Subepiglottic, Pharyngeal, and Palatal Cysts 96Clinical signs 97Diagnosis 97Treatment 98Prognosis 98Pharyngeal Paralysis 99Pharyngeal Neoplasia 99Pharyngeal Trauma 99Pharyngeal and Retropharyngeal Foreign Bodies 101Clinical signs 101Diagnosis 101Treatment 101Retropharyngeal Abscess 101Clinical signs 102Diagnosis 102Treatment 103Prognosis 103Further Reading 103Chapter 10: The Larynx 107Anatomy and Function 107Idiopathic Laryngeal Hemiplegia/Recurrent Laryngeal Neuropathy 108Prevalence 111Clinical signs 112Diagnosis 112Treatment 114Ventriculectomy and cordectomy 114Prosthetic laryngoplasty 115Temporary tracheotomy tubing 117Permanent tracheostomy 117Arytenoidectomy 117Laryngeal reinnervation 118Prognosis 118Right Laryngeal Hemiplegia 118Epiglottal Entrapment 119Clinical signs 120Diagnosis 120Treatment 121Prognosis 122Arytenoid Chondropathy (Arytenoid Chondritis; Arytenoid Chondrosis) 122Clinical signs 123Diagnosis 123Treatment 124Prognosis 125Laryngeal Neoplasia 126Fourth Branchial Arch Defects 126Clinical signs 127Diagnosis 127Treatment 128Prognosis 128Epiglottic Flaccidity 129Clinical signs 129Diagnosis 129Treatment 130Prognosis 130Epiglottic Hypoplasia 130Clinical signs 130Diagnosis 130Treatment 131Prognosis 131Epiglottitis 131Clinical signs 131Diagnosis 131Treatment 131Prognosis 131Dorsal Epiglottic Abscess 132Persistent Frenulum of the Epiglottis 132Laryngeal Web 133Perilaryngeal Accessory Bronchial Cyst 133Further Reading 133Chapter 11: Dynamic Airway Collapse During Exercise 137Pharyngeal Collapse 137Dynamic Dorsal Displacement of the Soft Palate 138Intermittent Epiglottal Entrapment 139Aryepiglottic Fold Collapse (Axial Deviation of the Aryepiglottic Folds) 139Clinical signs 139Diagnosis 140Treatment 140Prognosis 140Epiglottic Retroversion 141Dynamic Rostral Displacement of the Palatopharyngeal Arch 141Dynamic Laryngeal Collapse 141Further Reading 141Chapter 12: Postanesthetic Upper Respiratory Tract Obstruction 143Nasal Edema 143Bilateral Laryngeal Paralysis 143Further Reading 144Chapter 13: The Trachea 145Anatomy 145Tracheal Examination 145Surgery of the Trachea 146Tracheotomy intubation 146Permanent tracheostomy 147Tracheal resection and anastomosis 148External prosthesis to stent collapsed tracheal cartilages 149Laser surgery 149Congenital Tracheal Collapse (Collapsed Trachea) 149Clinical signs 150Diagnosis 150Treatment 150Tracheal Stenosis 151Clinical signs 152Diagnosis 152Treatment 152External Compression and Stenosis of the Trachea 152Tracheal Wounds 152Tracheal Neoplasia 153Intratracheal Prolapse of the Cricotracheal Membrane 153Tracheobronchial Foreign Body 153Further Reading 155Color plates (following page 156)Section III: Contagious Respiratory Diseases 157Chapter 14: Strangles 159Etiology and Pathogenesis 159Epidemiology 160Clinical signs 160Complications and sequela 162Diagnosis 164Treatment 167Control of an outbreak 169Prevention 169Further Reading 170Chapter 15: Equine Herpesvirus (Rhinopneumonitis) 171Equine Herpesvirus 4 (EHV-4) 171Equine Herpesvirus 1 (EHV-1) 172Diagnosis 173Treatment 173Prevention 174Equine Herpesvirus 2 (EHV-2) 175Chapter 16: Equine Influenza 177Diagnosis and Treatment 178Prevention of Influenza 179Chapter 17: Equine Viral Arteritis (EVA) 181Diagnosis and Treatment 182Prevention of EVA 182Chapter 18: Other Contagious Respiratory Diseases 183Hendra Virus (Equine Morbillivirus) 183Adenovirus 184African Horse Sickness 184Further Reading 185Section IV: Noninfectious Pulmonary Diseases and Diagnostic Techniques 187Chapter 19: Noninfectious Pulmonary Diseases 189Recurrent Airway Obstruction (Heaves) 189Diagnosis 190Treatment 192Respiratory Distress at Rest 194Systemic corticosteroid therapy 194Bronchodilator therapy 195Mild to Moderate Airway Obstruction 197Aerosolized corticosteroids 197Adrenal suppression 198Long-acting bronchodilator therapy 199Maintenance therapy 199Response to therapy 200Stable hygiene 200Summer Pasture-Associated Obstructive Pulmonary Disease 201Interstitial Pneumonias 202Lungworms 205Inflammatory Airway Disease (IAD) 206Diagnosis 207Treatment 210Exercise-Induced Pulmonary Hemorrhage (EIPH) 211Diagnosis 213Treatment 215Thoracic Neoplasia 217Smoke Inhalation 219Diagnosis 220Treatment 220Immunostimulant Therapy 222Bacterial and Viral Products 223Propionibacterium acnes 223Mycobacterium 224Parapoxvirus ovis 226Synthetic Immunostimulants 227Levamisole phosphate 227Interferon-alpha 227Further Reading 229Chapter 20: Techniques: Noninfectious Lower Respiratory Tract 233Endoscopic Examination of the Lower Respiratory Tract 233Arterial Blood Gas Evaluation 234Bronchoalveolar Lavage 237Technique 238Complications 240Lung Biopsy 240Technique 240Complications 241Advanced Respiratory Techniques 241Aerosol Delivery Devices 244Mechanical nebulizers 246Dry powder inhalant (DPI) devices 247Further Reading 248Section V: Lower Respiratory Tract Infectious Disease and Diagnostic Techniques 249Chapter 21: Juvenile Pneumonia 251Rhodoccocus equi 254Clinical signs 255Diagnosis 257Treatment 260Prevention 262Pneumocystis carinii 263Bronchointerstitial Pneumonia 265Further Reading 269Chapter 22: Pneumonia in Adult Horses 271Bacterial Pneumonia/Pleuropneumonia 271Clinical signs 273Diagnosis 274Thoracic ultrasound 275Thoracocentesis 276Thoracic radiographs 279Treatment 280Thoracostomy 282Complications 283Prognosis 285Fungal Pneumonia 285Pulmonary Metacestode Infection 287Further Reading 289Chapter 23: Techniques for Infectious Respiratory Disease 291Transtracheal Aspiration 291Thoracic Ultrasound 294Thoracocentesis 296Thoracic Radiography 299Further Reading 303Index 305