The influence of an aerosol with antibiotics on the wound healing following cautery disbudding of preweaned dairy calves compared with wound healing after the use of an aerosol wothout antibiotics

Abstract

Disbudding dairy calves is still a common procedure, since it prevents horn-related trauma and allows for safe cattle handling. Calves endure increased pain sensitivity until the wounds have healed, which takes weeks. Thus, it is of interest to evaluate practical strategies to hasten healing after disbudding. Most veterinary practioners in the Netherlands use an aerosol spray to promote wound healing after disbudding. CTC-spray®, an aerosol spray that contains chlortetracycline, is probably most commonly used for this purpose. Since the use of antibiotics for several indications is frequently questioned and there is a lack of evidence for the use of antibiotics for this purpose, the goal of this double blinded field study was to evaluate wound healing following cautery disbudding using an aerosol with or without antibiotics. 255 dairy calves on 37 farms of 2 veterinary practices were disbudded using a standard cautery disbudding protocol. After disbudding, the two horn buds of each calf were treated with two different sprays. We alternately treated the left and right horn bud with an aerosol spray that contains chlortetracycline (CTC-spray®) and with a blue aerosol spray without antibiotics, called Keno™Fix. The primary outcomes were lesion score (LS) and wound diameter (WD) measured at 1 week and 4 weeks post disbudding. The LS was scored on a scale of 1 to 3, with LS = 1 representing normal healing with no scabs or discharge present, LS = 2 having scabs or raised crusts and LS = 3 showed moist or dried purulent discharge. The WD was measured in millimeters at the widest point of the inner edges of the wounds. Statistical analysis of the WD showed a significant difference at week 4 that was estimated at 0.35 mm in favor of CTC-spray®. This difference is too small to be of clinical importance. The odds to get a LS =2 or 3 was 2.5 times higher for Keno™Fix than for CTC-spray®. But, since this is not combined with a difference in wound diameter it is arguable whether the higher LS is really something that causes delayed healing or whether it is a normal stage of wound healing. The decision to use one of both sprays depends on the goals of the veterinary practice and the farmer, considering that we want to decrease the use of antibiotics, but the surface of the wound will be not as good looking, when we do.