This prospective study evaluated short-term (up to 12 days) forelimb function after scalpel compared with laser onychectomy in cats. The authors used pressure platform gait analysis (PPGA) as an indicator of discomfort. Twenty cats, ranging in age from 6 to 24 months, were evenly and randomly assigned to 2 groups: unilateral left forelimb scalpel onychectomy and unilateral left forelimb CO2 laser onychectomy. Subjective evaluation was initially used after surgery to monitor for such complications as neurapraxia, tissue ischemia, and muscle damage and to determine whether rescue analgesia was needed. PPGA was performed the day before surgery and 1, 2, 3, and 12 days after the procedures. Based on the statistical results, on days 1 and 2 the cats in the laser surgery group were less lame than those in the scalpel group. No significant differences were found in ground reaction forces (GRFs) between the groups on day 3; however, by day 12, cats in the laser group had a significantly higher peak vetical force ratio but still no difference in GRFs. Limb function is improved when unilateral onychectomy is done with the CO2 laser rather than the scalpel. Laser excision also minimizes intra- and postoperative hemorrhage, postoperative swelling, and need for bandages or tourniquets.
COMMENTARY: Various studies have been done over the past few years to evaluate laser versus scalpel onychectomy. This study used pressure platform gait analysis to measure actual lameness as an indicator of pain and discomfort, rather than the more common (and possibly more variable) blood cortisol concentrations. The results are similar for both techniques of evaluation: laser onychectomy results in less surgical hemorrhage, requires no tourniquet, and results in decreased postsurgical lameness and pain, arguing for practitioners to move to this method.
Evaluation of short-term limb function following unilateral carbon dioxide laser or scalpel onychectomy in cats. Robinson DA, Romans CW, Gordon-Evans WJ, et al. JAVMA 230:353-358, 2007.