Which inhalant anesthetics are commonly used in small animal practice?

• A. Nitrous oxide only.
• B. Halothane only.
• C. Desflurane only.
• D. Isoflurane and sevoflurane.

Answer: (D)

In small animal anesthesia, the go-to inhalant anesthetics are isoflurane and sevoflurane because they offer reliable, controllable anesthesia with rapid onset and recovery and have favorable cardiovascular safety and wide clinical use. Isoflurane is inexpensive and well understood, providing smooth maintenance anesthesia with minimal metabolism, making it a workhorse for many procedures. Sevoflurane, on the other hand, is less irritating to the airways, which makes mask induction easier in anxious or feline patients, and its lower blood-gas solubility generally allows quicker induction and faster recovery. Together, they cover the common needs of routine surgeries and diagnostics, with clinicians choosing between them based on species, temperament, and cost.

Nitrous oxide is not used alone to produce surgical anesthesia in small animals; it is typically adjunctive and insufficient by itself for maintenance. Halothane, though once common, carries risks such as hepatotoxicity and cardiac sensitivity that have led to its decline in routine practice. Desflurane is less favored in small animals due to higher cost, the need for special equipment, and potential airway irritation, so it’s not commonly used.