Experiments that involve some minor stress or pain (short-duration pain) to vertebrate animal species.
(Examples and Comments)
Exposure of blood vessels or implantation of chronic catheters with anesthesia; behavioral experiments on awake animals that involve short-term stressful restraint;maternal deprivation with substitution of punitive surrogates; immunization employing Freund's
adjuvant; noxious stimuli from which escape is possible; surgical procedures under anesthesia that may result in some minor post-surgical discomfort. Category C procedures incur additional concern in proportion to the degree and duration of unavoidable stress or discomfort.