The granulation (t)issue: A narrative and scoping review of basic and clinical research of the equine distal limb exuberant wound healing disorder.
Authors: Anantama Nadia Ayurini, Du Cheyne Charis, Martens Ann, Roth Susanne Pauline, Burk Janina, De Spiegelaere Ward, Michler Jule Kristin
Journal: Veterinary journal (London, England : 1997)
Summary
Exuberant granulation tissue (EGT) represents a significant clinical challenge in equine wound management, yet its underlying mechanisms remain poorly understood and evidence-based prevention and treatment strategies are limited. This comprehensive narrative and scoping review synthesised 327 basic research studies and 35 controlled clinical trials to examine what drives EGT development—a multifactorial disorder involving fibroblast hyperproliferation, impaired keratinocyte differentiation, inadequate wound contraction, aberrant vascularisation and persistent inflammation. The 35 clinical trials reviewed were predominantly conducted in university settings using surgically created wounds in 230 horses, 18 ponies and 14 donkeys, raising concerns about their generalisability to naturally occurring injuries seen in everyday practice. A critical finding is the lack of consistent, evidence-based recommendations for EGT management, alongside a significant knowledge gap between what basic research reveals about wound biology and how this is translated into clinical trial design. For equine professionals managing distal limb wounds, this review underscores the urgent need for multi-centre clinical studies in realistic field conditions with larger animal numbers, whilst highlighting that future EGT research must integrate mechanistic understanding from basic science to develop genuinely effective preventative and therapeutic protocols.
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Practical Takeaways
- •Current treatment strategies for EGT lack robust evidence-based support; practitioners should critically evaluate published protocols given the predominance of artificially-induced wound studies that may not reflect field conditions
- •Understanding that EGT is multifactorial (involving fibroblast hyperproliferation, vascular dysfunction, and chronic inflammation) suggests no single treatment modality will be universally effective—consider combination approaches tailored to individual wound presentation
- •Advocate for clinical trials using naturally occurring distal limb wounds on your clients' horses, as research is heavily skewed toward controlled university settings and may not translate to practical farm management situations
Key Findings
- •35 controlled clinical trials on EGT treatment were identified, all conducted in university hospitals with surgically induced non-infected wounds in 230 horses, 18 ponies, and 14 donkeys
- •EGT development involves hyperproliferating fibroblasts, malfunctional keratinocyte differentiation, suboptimal wound contraction, dysfunctional vascularization, and chronic inflammation
- •Current evidence lacks multi-centre studies using naturally occurring wounds with adequate animal numbers and appropriate control populations
- •Basic mechanisms underlying EGT remain poorly understood despite significant clinical impact on equine wound care outcomes