EVALUATION OF LOW-LEVEL LASER THERAPY ON PRIMARY HEALING OF EXPERIMENTALLY-INDUCED FULL-THICKNESS TEAT WOUNDS IN DAIRY-CATTLE

Objective-The purpose of this study was to evaluate the effect of low- level laser therapy (LLLT) on sutured wounds of the teat in dairy catt le. Study Design-By using the Latin square design, the effect of LLLT was evaluated by radiography, measurement of microcirculation flow, hi stopathology, tensiometry, and hydroxyproline analysis. Animals or Sam ple Population-Sixteen teats of four dairy cattle. Methods-Full thickn ess wounds were made on the cranial surface of the teats. Teats were d istributed into four groups; group A and B wounds were closed with a G ambee pattern, group C and D wounds were closed with three-layers of c ontinuous suture pattern. Group B and D wounds were treated with 3.64 J/cm(2) of LLLT using a helium-neon system continuous wave (632.8 nm) output of 8.5 mW. Results-The teat wall in non-LLLT groups was signifi cantly thicker than in LLLT groups on day 7, 14 and 21. The mean blood flow differences between control and sutured sites in LLLT groups wer e significantly lower than those in non-LLLT groups. The morphology of the epidermis in LLLT groups more closely resembled the normal epider mis than that of non-LLLT groups. Collagen fibers in LLLT groups were denser, thicker, better arranged and more continuous with existing col lagen fibers than those in non-LLLT groups. The mean tensile strength was significantly greater in LLLT groups than in non-LLLT groups. Conc lusion-The LLLT affects various aspects of the healing process, includ ing minimizing inflammation, formation of edema, improvement of skin r egeneration and enhancement of collagen synthesis. Clinical Relevance- The LLLT could accelerate healing of sutured wounds of the teat in dai ry cattle. (C) Copyright 1997 by The American College of Veterinary Su rgeons.