The area of injection or incision should be cleaned with alcohol or other suitable disinfectant. In order to better visualize veins dilation can be accomplished warming the animal with a low-wattage light bulb for 5 to 15 minutes prior to venipuncture. This also aids by providing additional light. Several veins are used, but there is considerable variation among individual animals in their size and usefulness. Chronic indwelling catheters may be surgically placed in the jugular vein.
Light anesthesia is recommended.
Injections are made in the lower abdominal quadrant, off the midline, taking care to avoid the urinary bladder, bowel and liver. Aspirate before injection to insure proper placement. The skin of the guinea pig is thick and tough, especially over the shoulders. The use of short, heavy gauge needles are recommended, e.g. 20 g, 1-inch. Good restraint is necessary to avoid injury.