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Many local or regional anesthetic drugs are available that can produce reversible loss of autonomic, motor, and sensory function with acceptable onset times and predictable duration [1]. These drugs vary in their potency, toxicity, and cost [2]. Lidocaine hydrochloride 2% and mepivacaine hydrochloride 2% have become two of the most widely used local anesthetic agents in cattle due to limited toxicity and low cost. Lidocaine hydrochloride has a duration of 90–180 minutes, is three times more potent than procaine, and diffuses into tissues more widely [1, 3]. Mepivacaine has a duration of 120–180 minutes, which is longer than lidocaine; however, the time to onset of anesthesia is similar. Although, bupivacaine has an even longer duration of action (up to 360 minutes), it is not recommended for routine use in cattle due to risk of inadvertent intravenous administration which could lead to toxic effects [4].

The addition of a vasoconstrictor such as epinephrine (5 μg/ml) to the local anesthetic solution (0.1 ml epinephrine 1 in 1000 added to 20 ml of local anesthetic) increases the potency and duration of activity of both regional and epidural anesthesia. However, local anesthetics containing epinephrine 1 in 200 000 should not be used in wound edges or in the subarachnoid space due to the risk of causing tissue necrosis and spinal cord ischemia [1].