Research Update: Laser vs. scalpel onychectomy in cats

In this prospective study at a university veterinary hospital, 20 healthy adult cats (6 to 24 months of age) were divided into two groups and underwent left forelimb unilateral scalpel or CO2 laser onychectomy. In the scalpel group, a tourniquet was used during surgery and a bandage was applied after surgery. All cats received butorphanol tartrate during the first 24 hours after surgery. Pressure platform gait analysis was performed before and one, two, three, and 12 days after onychectomy to measure the following ground reaction forces: peak vertical force, vertical impulse, and the ratio of the left forelimb peak vertical force to the sum of the remaining limbs (peak vertical force ratio).

The study's results revealed that cats in the laser surgery group had significantly higher ground reaction forces on Days 1 and 2 and a significantly higher peak vertical force ratio on Day 12 compared with the scalpel group. The authors suggest that higher ground reaction forces are an objective measure of less postoperative lameness, which implies less pain in the laser group. When postoperative ground reaction forces were compared with preoperative forces, the findings were more similar in the laser treatment group than in the scalpel treatment group. The exact mechanism for a difference in postoperative pain between laser and scalpel surgery remains unclear.

COMMENTARY

Feline onychectomy is frequently performed in small-animal practice. Ensuring patient comfort during recovery is critical, along with avoiding complications such as tissue ischemia, necrosis, neurapraxia, hemorrhage, and claw regrowth. The improved limb function scores in laser-treated patients, as described in this report, support clinicians who prefer the speed and precision of this technique. The study results also suggest that tourniquets and bandages are unnecessary in patients undergoing laser onychectomy. Clinicians who prefer scalpel onychectomy may argue that the cost of a laser unit should be considered and that proper surgical technique and use of postoperative analgesics could mitigate the difference in lameness scores noted in this small academic study.

Robinson DA, Romans CW, Gordon-Evans WJ, et al. Evaluation of short-term limb function following unilateral carbon dioxide laser or scalpel onychectomy in cats. J Am Vet Med Assoc 2007;230:353-358.

The information in "Research Updates" was provided by Veterinary Medicine Editorial Advisory Board member Joseph Harari, MS, DVM, DACVS, Veterinary Surgical Specialists, 21 E. Mission Ave., Spokane, WA 99202.

Joseph Harari, MS, DVM, DACVS