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.
The lower back muscles should be used to avoid self-induced foot trauma that may result from ischiatic nerve irritation from injection of the thigh muscles. Aspirate before injection to insure proper needle placement. If blood is obtained upon aspiration partially withdraw the needled to a subcutaneous position and redirect the needle into the muscle. An assistant is usually needed. The amount of blood needed and other factors will govern the method and sites of collection.