The following list includes only the commonly used anesthetic agents in pigs. A list of other anesthetics suitable for specific procedures and additional information about the effects, mode of action, metabolism, and side effects of these agents are available in the CMU office, extension 6555.

For both injectable and inhalant procedures, pigs should be medicated with an anticholinergic such as atropine (0.04-0.05 mg/kg intramuscularly or subcutaneously) or glycopyrrolate (0.02 mg/kg intramuscularly or subcutaneously) to reduce salivation and maintain heart rate.

INJECTABLE AGENTS:

Ketamine + acetylpromazine - 22 mg/kg ketamine and 1.1 mg/kg acetylpromazine (can be mixed in the same syringe) by intramuscular injection.  COMMENTS: Suitable for minor procedures including intubation for inhalation anesthesia; large injection volumes may make for difficult administration.

Ketamine + xylazine - 20 mg/kg ketamine and 2 mg/kg xylazine by intramuscular injection.  COMMENTS: It is important to give atropine with this combination because xylazine causes heart block and hypotension in pigs; suitable for minor surgery.

Pentobarbital - 24 mg/kg  by intravenous injection, given to effect.  COMMENTS: Reduce dose by one-half to two-thirds when given with other agents (as is usually the case because pigs normally have to be chemically restrained for intravenous injections); apnea may occur so a ventilator should be available; for procedures lasting longer than 2 hours pentobarbital is undesirable due to prolonged recovery; best suited for non-survival procedures because of respiratory depression and poor analgesia.

Telazol – Administer 6.6 mg/kg by intramuscular injection.  COMMENTS: Suitable for minor procedures including intubation for inhalation anesthesia; can be supplemented with Thiopental (2 – 3 mg/kg by intravenous injection to effect) or pentobarbital (3 mg/kg by intravenous injection to effect).

Telazol + xylazine – Dilute Telazol with large animal Xylazine (100 mg/ml) and administer the combination at a dose of 5.5 – 6.5 mg/kg of Telazol.  COMMENTS:  Suitable for minor procedures including intubation for inhalation anesthesia.

Thiopental - 6.6-8.8 mg/kg by intravenous injection.  COMMENTS: Suitable for only very brief procedures such as intubation prior to inhalation anesthesia; like pentobarbital it has poor analgesia and shows respiratory depression - ventilatory support should be available.

INHALANT AGENTS:

Note:  1.)  Inhalation anesthetics are administered to pigs via an endotracheal tube.  Consequently the animals must be pre-anesthetized and intubated prior to administration of the gas.  Intubation is usually accomplished with the administration of Telazol (alone or in combination with Xylazine) and, if necessary, a short acting barbiturate (see Thiopental above).  The dose of Thiopental is reduced by ½ to 2/3 when used with another agent.  Intubation can be difficult in pigs and requires both training and practice. Please contact the CMU for instruction.  2.)  Inhalation anesthesia is augmented by the use of nitrous oxide delivered at a proportion of 30-70% of the inspired gases.  It will reduce the amount of inhalant agent required.

Halothane - 4-5% of inspired gas for induction, 0.5-2.0% of inspired gas for maintenance, delivered through an endotracheal tube with a vaporizer.  COMMENTS: May cause malignant hyperthermia in swine, particularly light colored breeds such as Poland China, Landrace, and Pietrain; requires a vaporizer, waste gases should be scavenged for personal safety reasons, rapid induction and recovery.

Isoflurane - 3-4% of inspired gas for induction, 0.5-2.0% of inspired gas for maintenance, delivered through an endotracheal tube with a vaporizer.  COMMENTS: Requires a vaporizer, waste gases should be scavenged for personal safety reasons, rapid induction and recovery; may be cardioprotective.