Laryngeal assessment in dogs: a clinical review

This article reviews the literature describing the anaesthetic and ancillary drugs used during the assessment of laryngeal function in dogs, and summarises the evidence for their use in clinical practice. A review of the literature was conducted using PubMed and Google Scholar, with the search terms ‘laryngeal assessment dogs’, ‘laryngeal collapse’, ‘laryngeal paralysis’, ‘premedication laryngeal assessment’, ‘induction agent laryngeal assessment’ and ‘dogs’. Further studies and reports were obtained from the reference lists of the retrieved papers. Related anaesthesia textbooks were also reviewed. Drugs used to induce anaesthesia affect laryngeal function by diminishing the laryngeal reflex. Based on the current literature, premedication using acepromazine and an opioid allows for the assessment of laryngeal examination without impairing laryngeal motion. Dexmedetomidine in combination with an opioid may offer an alternative, but there are no studies comparing these sedative drugs directly. Examination times were shorter with propofol compared to alfaxalone, while ketamine was not recommended as an anaesthetic induction agent for this purpose. The use of doxapram hydrochloride may be helpful, particularly when airway assessment remains equivocal. At low doses, doxapram causes minimal increases in arterial blood pressure and heart rate.