The effect of a topical anesthetic on the sensitivity of calf dehorning wounds.

The objective was to determine the effect of a topical local anesthetic on the sensitivity of dehorning wounds in calves. Thirty 2-mo-old Holstein-Friesian calves were randomly allocated to sham dehorning control (CON), scoop dehorning without treatment with topical anesthetic (SnoTA), or scoop dehorning with an application of a topical anesthetic (STA). Sensitivity was measured by providing mechanical stimulation to the dehorned wound and peri-wound area using von Frey monofilaments calibrated at 10 and 300 g. Calf responses were categorized as absent, minor, moderate, or severe. Sensitivity measurements were performed before treatment and at various time points up to 24h posttreatment. Sham dehorned calves displayed unchanging absent or minor responses to stimulation. Regardless of whether topical anesthetic was applied, scoop dehorned calves were more likely to display minor, moderate, or severe responses than sham dehorned control calves, and responses tended to be most extreme at 4h postdehorning. Calves in the STA group tended to be less likely to display minor, moderate, or severe responses than calves in the SnoTA group at most time points (exception at 4h postdehorning). Responses were significantly more likely to be less severe in STA calves than in SnoTA calves at 40 min and 1.5h following dehorning. Thus, the use of the topical anesthetic for calves reduced the short-term sensitivity of scoop dehorning wounds.