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Small animal patients may need to be anesthetized in the periparturient period for emergency, nonobstetric reasons, elective ovariohysterectomy, or cesarean section. In each case, the physiologic changes in the dam must be accounted for in designing an anesthetic protocol, but the requirements of the fetuses will be different. Subsequent to birth, the neonatal animal may need to be anesthetized, and the unique physiology and pharmacology at this age is described.

The first few minutes after a neonate's birth may determine the quality of its entire life. Immediate care includes prevention of hypothermia, clearing of nasal and oral passages, stimulation of ventilation and oxygenation, and, in a few cases, advanced life support. Any additional stress during the first weeks of life can also result in neonatal morbidity and mortality. Care of the diseased newborn must focus not only on treatment of the underlying disease but on aggressive supportive care. A safe, warm, clean, proper environment and adequate nutrition are essential.

The management of perioperative pain starts with the use of approaches to minimize anxiety and distress before the procedure. The administration of analgesics or local anesthetics before the start of surgery reduces the nociceptive input occurring during the procedure and reduces the need for postoperative analgesics. As the animal recovers from anesthesia, it is important to administer analgesics to minimize the patient's experience of pain and to continue this therapy through at least the first 12 to 24 hours. Techniques that provide a continuous level of analgesia are more effective than those that allow the pain to return.

Opioids are useful and potent drugs for the management of pain in small animal patients. They have a wide therapeutic index and can be given by a number of different routes. Some of these techniques (e.g., epidural and intraarticular) allow for the production of profound analgesia in a localized area of the body while limiting the dose and the side effects, and others provide a noninvasive method for the delivery of continuous analgesia (e.g., transdermal administration).

The administration of drugs by the epidural route is a safe and effective method for providing analgesia before, during, and after a surgical procedure. Local anesthetics administered by this route block nociceptive input as well as providing excellent muscle relaxation for surgery. The use of local anesthetics may be associated with short-term motor dysfunction and hypotension as a result of sympathetic blockade. Morphine given by the epidural route also provides effective analgesia and has the advantages of giving more prolonged analgesia with no effect on either motor or sympathetic pathways.

Surgery is painful and it behooves us, as people who care for and take care of animals, to prevent their suffering whenever possible. Recent developments in the understanding of nociceptive physiology underscores this prospective, rather than retrospective, approach to the management of pain. We have the armamentarium to do this and there are very few deleterious side effects when appropriate treatments are used.

The maintenance of anesthesia with injectable drugs provides a safe alternative to inhalant techniques, provided that the basic needs of the patient are met. The standard drugs (e.g., thiobarbiturates, methohexital, ketamine) can be used, economically and safely, to provide a short duration of anesthesia, but the best drugs for more prolonged procedures are more expensive (e.g., alfentanil, fentanyl, propofol) and require more sophisticated equipment to provide optimal conditions.