Update on Noninfectious Inflammatory Diseases of the Lower Airway

Clinical Approach to Commonly Encountered Problems

“…[215][216][217][218] Included in this syndrome are inflammatory airway disease (IAD, mild to moderate equine asthma) and recurrent airway obstruction (RAO, severe equine asthma). [215][216][217][218] Included in this syndrome are inflammatory airway disease (IAD, mild to moderate equine asthma) and recurrent airway obstruction (RAO, severe equine asthma).…”

“…207 Although viral respiratory diseases can be seen in any age horse, they are particularly common in weanling and yearling horses. [215][216][217][218] The risk of developing RAO is threefold when one parent is affected and almost fivefold when both parents are affected. 231,232 Horses with RAO are typically over 7 years of age, and a familial predisposition has been identified.…”

“…[215][216][217][218]249,252 Other tests that may be useful include a hay challenge to induce disease, histamine provocation tests to assess airway reactivity, and bronchodilator response testing, typically with atropine, N-butylscopolammonium bromide, or albuterol. Several additional diagnostic tests can be helpful in the evaluation of equine asthma, especially pulmonary function testing.…”

“…255 Dyspnea refers to the sensation of arduous, uncomfortable, or difficult breathing that occurs when the demand for ventilation exceeds the patient's ability to respond. 255,257,217 In severe cases, cyanosis may be seen. The clinical signs of respiratory distress vary with the severity and 5 1 251 origin of impaired gas exchange.…”

“…256 Because dyspnea describes a subjective feeling, it is technically a symptom rather than a clinical sign and thus not strictly applicable in veterinary medicine although the term is often used. 257,217 Weight loss may be seen in association with decreased feed intake and a high energy demand for respiration. Clinical signs commonly observed in horses with respiratory distress include flared nostrils, exercise intolerance, inactivity, exaggerated abdominal effort, abnormal respiratory noise (stertor or stridor), anxious expression, extended head and neck, and synchronous pumping of the anus with the respiratory cycle.…”