Classification of Modern Pet Anesthetics

       Currently, pet anesthetics are mainly classified based on two dimensions: medication method and anesthetic effect.

       1.Inhalation Anesthetics and Non-inhalation Anesthetics

       Pet anesthetics can be classified into inhalation anesthetics and non-inhalation anesthetics based on the route of administration.

       Inhalation anesthetics (also known as volatile anesthetics) exist in liquid or gaseous form at room temperature and atmospheric pressure. Their characteristic feature is the ease of controlling dosage and depth of anesthesia. Common types include nitrous oxide, cyclopropane, anesthetic ether, methoxyflurane, enflurane, halothane, isoflurane, desflurane, sevoflurane, etc.

        Non-inhalation anesthetics (also known as injectable anesthetics) are characterized by their ability to induce anesthesia relatively quickly and controllably. Common types include barbiturates (phenobarbital, pentobarbital, thiopental, thiamylal, methohexital, amobarbital), arylcycloalkylamines or cyclohexylamines (ketamine, tiletamine, phencyclidine), and others (propofol, etomidate, alphaxalone, chloralose, propanidid, metomidate, etc.).

        2.General Anesthetics and Local Anesthetics

        Pet anesthetics can be classified into general anesthetics and local anesthetics based on their anesthetic effects.

        The first local anesthetic of clinical significance was the alkaloid cocaine, discovered in 1880 and used in surgeries for dogs and horses in 1885. In 1905, the first synthetically produced local anesthetic, procaine, was developed. Local anesthetics can be further divided into amino esters (procaine, chloroprocaine, tetracaine) and amides (lidocaine, mepivacaine, bupivacaine, etidocaine, prilocaine, ropivacaine, etc.) based on their chemical structure. Local anesthetics are primarily used for regional anesthesia, and their specific applications are shown in Table 1.

        General anesthetics refer to a class of drugs that can cause loss of consciousness and all bodily sensations. They are diverse in type, including barbiturates, steroids, phenols, alcohols, inert gases, halogenated hydrocarbons, carbon dioxide, etc. The potency of anesthesia is related to their lipid solubility.