Studies on the effect of various topical agents on second intention wound healing of the equine distal limb

Abstract

Traumatic wounds of the distal limb are common in horses. These wounds are often left to heal by second intention because of substantial tissue avulsion and contamination. In the horse second intention healing is often problematic and wounds are susceptible to the production of excessive granulation tissue, which inhibits the progression of healing.

There have been many products recommended to enhance second intention wound healing in horses, however no product has proved to be a treatment panacea. Marijuana (Cannabis sativa) contains more than 60 biologically active chemical agents that have been shown to have potent antibacterial and anti-inflammatory activity as well as the ability to improve elements of healing in a rat skin wound healing model. The current study aimed to investigate the effects of one resin, cannabadiol, on second intention wound healing in horses. The first part of our study was to determine if daily topical application of cannabidiol, in combination with a carrier of manuka honey, would improve wound healing variables in an equine model of second intention wound healing.

Several studies have shown manuka honey enhances second intention would healing in horses in equine wound healing models. As the unique manuka factor (UMF) increases so does the antimicrobial activity of the manuka honey. Most studies have focused on UMF 20 honey in contaminated and uncontaminated equine wound healing models. The second part of our study examined the effect of different UMF honey on second intention wound healing, and compared this to the use of Melaleuca honey. Our hypothesis was that increasing the UMF rating would improve wound healing and that Melaleuca honey would not enhance second intention would healing in the horse.