Equine wound care: Everything old is new again

Equine wound care: Everything old is new again

Renewed attention is being paid to older treatment options, especially for antibiotic-resistant pathogens
Aug 01, 2011

Humans and the animals they have domesticated and cared for historically have been susceptible to dermal trauma and wounds. Developing healing agents for those wounds has been crucial to survival.

Photo 1: This horse suffered an extensive but relatively superficial injury to the inner left thigh that required long-term management. Standard therapy involves cleaning the area, removing devitalized tissue and applying topical medications that usually include creams and various antibacterial ointments. Alternatively, practitioners could try other nonantibiotic agents on such a wound. (Photos courtesy of Dr. Marcella)
Substances derived from plants, animals and minerals have been formulated to help stop bleeding, reduce inflammation, fight bacteria and promote healing. Clay tablets found in Mesopotamia dating to nearly 2,500 B.C. provide the earliest documented records of topical wound treatment, and such treatments were further refined by the Egyptians, Greeks and Romans and on through to the healers of the Middle Ages. Wars exacerbated the necessity of wound care, and many treatments for both horses and humans were first tried on the battlefield.

Photo 2: The photo depicts a laceration 10 days after injury. This wound likely would have responded well to primary suture repair, but the injury wasn't found in time, and second intention healing with possible later repair was attempted. Use of various antimicrobial agents, such as silver, honey or other products, would help remove bacterial infection and begin a healing process when applied under a bandage. These products will help produce healthy granulation tissue but won't adversely affect wound contracture, making later cosmetic repair possible. (Photos courtesy of Dr. Marcella)

The 19th century discovery of disinfectants, along with a greater understanding of the causes of infection and factors associated with disease spread, greatly accelerated our ability to treat dermal wounds. The discovery, rapid development and quick acceptance of antibiotics in the 20th century was likely the greatest single step forward in wound care; however, the shift to antibiotics also meant a decline in use of many of these former remedies.

The emergence of antibiotic-resistant strains of pathogens in the 21st century, however, and the decrease in the production of newer antibiotics capable of fighting these often multi-antibiotic-resistant bugs has led to a revival of sorts, with renewed attention being paid to many of the older treatment methods. Many of these options were never fully researched or used previously, and they may well hold the key to being able to stay ahead of infections in the coming century (Photos 1 and 2).

"Old school" treatment options

Fresh science applied to older products and remedies may produce useful information and give equine practitioners a few more options, even though they may be "old school" options when treating dermal wounds.

Rose Cooper, PhD, a lecturer in microbiology at the Centre for Biomedical Sciences, University of Wales Institute Cardiff, U.K., has published an exhaustive review of evidence for the use of topical antimicrobial agents in wound care. She also urges caution in interpreting this information.

"Overall, the evidence concerning the efficacy of topical antimicrobial agents in the management of wounds is confusing," Cooper writes. "It must be remembered that it [published studies and evidence of effectiveness] originates from multiple sources, which are not directly comparable."

Cooper lists the following factors as variables that cloud what we know from studies of topical antimicrobial agents: concentration tested, contact time, species used for testing, temperature and number and type of organisms present. "Larger, better-designed trials to assess clinical efficiency and cost implications are necessary," says Cooper. But there's still value in reviewing what we do know—and possibly where and how this information may be used—when faced with the treatment of a dermal injury."