Which of the following is used to administer oral medication capsules or boluses into an animal?

The use of a balling gun is specifically designed for administering oral medications, particularly capsules or boluses, into animals. This tool allows for the safe and efficient delivery of larger doses of medication directly into the animal's throat, minimizing the risk of choking or aspiration. The design of the balling gun includes a plunger mechanism that enables the user to push the capsule or bolus past the animal's tongue and into the esophagus, where it can then be swallowed.

While a drench gun also administers liquid medications, it is not suitable for capsules or boluses. Hypodermic syringes are primarily for injectable medications and do not deliver oral treatments. Needle holders are used to handle needles and sutures during surgical procedures, making them unsuitable for administering oral medications. Thus, the balling gun is the most appropriate tool for the task of administering solid oral medications.