In veterinary surgery, which instrument helps ensure precise drilling of holes in bone?

The instrument that aids in ensuring precise drilling of holes in bone is the drill guide. A drill guide is specifically designed to assist surgeons in targeting the correct entry point and angle for drilling into bone, which is crucial for procedures such as orthopedic surgeries. By providing a stable and accurate reference, the drill guide minimizes the risk of damage to surrounding tissues and ensures that the holes created are appropriately positioned for the insertion of screws, pins, or other fixation devices.

In contrast, the depth gauge is primarily used to measure the depth of a drilled hole, rather than to guide the drilling itself. It is useful for ensuring that the drill goes to the required depth but does not help with the placement of the drill bit in terms of direction or angle. The TECA retractor is utilized for holding back soft tissues to provide better visibility and access to the surgical site but does not play a role in drilling. Webb bolts are used in fixation rather than in the drilling process and serve a different purpose entirely, as they are fasteners used to stabilize bone fragments during surgical repair.

Thus, the drill guide is the correct choice as it directly contributes to the precision and accuracy of bone drilling in surgical procedures.