Veterinary Anesthesia
Anesthesia in animals has many similarities to human anesthesia, but some differences as well. Local anesthesia is primarily used for wound closure and removal of small tumors. Lidocaine, mepivacaine, and bupivacaine are the most commonly used local anesthetics used in veterinary medicine. Sedation without general anesthesia is used for more involved procedures. Sedatives commonly used include acepromazine, hydromorphine, midazolam, diazepam, xylazine, and medetomidine. α2 agonists like xylazine and medetomidine are especially useful because they can be reversed, xylazine by yohimbine and medetomidine by atipamezole. Xylazine is approved for use in dogs, cats, horses, deer, and elk in the United States, while medetomidine is only approved for dogs. Most surgeries in ruminants can be performed with regional anesthesia.
General anesthesia is commonly used in animals for major surgery. Animals are often premedicated intravenously or intramuscularly with a sedative, analgesic, and anticholinergic agent (dogs frequently receive buprenorphine, acepromazine, and glycopyrrolate). The next step is induction, usually with an intravenous drug. Dogs and cats commonly receive thiopental (no longer allowed in the UK), ketamine with diazepam, tiletamine with zolazepam (usually just in cats), and/or propofol. Alfaxalone is a steroid anaesthetic used in many practices in the UK to induce anaesthesia in cats and sometimes dogs. It is similar in physiological effect but different in composition to the now withdrawn Saffan. Horses commonly receive thiopental and guaifenesin. Following induction, the animal is intubated with an endotracheal tube and maintained on a gas anesthetic. The most common gas anesthetics in use in veterinary medicine are isoflurane, enflurane, and halothane, although desflurane and sevoflurane are becoming more popular due to rapid induction and recovery.
Read more about this topic: Veterinary Surgery