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The use of local anesthetics is helpful in isolating pain in the lameness examination, but proper restraint in lateral recumbency is required for administration. The application of anesthetics should only be done after local examination of the affected area and any other diagnostics (including hoof testing, radiography, and ultrasound) have been performed. Lidocaine is used because of its rapid onset of action (3–5 minutes) and short duration (20–30 minutes) (Figure 16.9).

Figure 16.9 Vascular perfusion used for local anesthesia as well as treatment.

Most often the first anesthetic administered will be a vascular perfusion of all structures distal to and including the fetlock. For regional limb perfusion, place a tourniquet (using IV tubing or bicycle inner tube) proximal to the fetlock. In a limb free of edema, wrap tightly enough to identify the dorsal digital vein and administer 15–25 ml of lidocaine. Maintain the tourniquet for 10 minutes before releasing the animal to observe for lameness. If no improvement in gait occurs, the animal is restrained again. Regional whole limb perfusion or a four‐point block may be used to isolate lameness below the elbow or stifle. To perfuse the whole limb, 30 ml of lidocaine in 50 ml of saline is administered with a tourniquet above the carpus or tarsus. This can be performed standing in a squeeze chute. The practitioner may also consider the use of intra‐articular anesthesia for individual joints; 10 ml of lidocaine is sufficient for each joint except the stifle, which usually requires a larger volume.

In beef cattle with forelimb lameness, if the cause does not appear to be in the hoof, it is often in the shoulder. This is suspected to be due to inadvertent abduction during mounting or due to falls and displacement of the limb laterally. Rear limbs can be difficult to evaluate and require more patience and effort to examine. The coxofemoral joint must not be overlooked as a cause of lameness in the rear limb. These too can be injected with anesthetics to rule in or out lameness.