Differences in second‐intention wound healing between horses and ponies: macroscopic aspects

Abstract

Summary Second‐intention healing of deep wounds was studied in 5 horses and 5 ponies. Standardised wounds were created on the distal limbs and hind quarters. Wounds on the metatarsi extended onto the metatarsal bone; the depth of the wounds in the femoral biceps muscle was 18 mm. The wound margins were marked by tattoos. Photographs were taken at weekly intervals to determine the wound area. The relative contribution of contraction and epithelialisation to wound closure was quantified by means of the tattoos. Swelling of the limbs was measured; and regularity and aspect of the granulation tissue were semi‐quantitatively scored. Second‐intention wound healing occurred significantly faster in ponies than in horses, and muscle wounds healed significantly faster than metatarsal wounds. These marked differences reflected the greater contribution of contraction to wound healing. Moreover, demarcation was seen earlier and a healthy granulation bed developed more rapidly in ponies, whereas in horses the granulation tissue remained irregular and purulent for longer. Healing of the metatarsal wounds of horses differed markedly from that of all other wounds: these wounds increased to almost twice their original size in the first 2 weeks, exuberant granulation tissue was persistent, epithelialisation started later, and contraction played a minor role in wound closure. Limb swelling was greater in horses than in ponies. Periosteal new bone formation was more extensive, and was active over a longer period in the metatarsal bones of horses than of ponies. From this study it is concluded that second‐intention healing of deep wounds occurs faster in ponies than in horses. This difference can be largely attributed to a more pronounced and faster wound contraction in ponies than in horses. Therefore, attempts to improve second‐intention wound healing in clinical practice should be directed at stimulation of wound contraction.

Blunt Force Trauma in Veterinary Forensic Pathology

“…19,20,24,37,44 This pitfall has recently been highlighted, since differences in healing vary greatly even between genetically close species. 9,53,79,80 As an example, it has been shown that healing starts earlier and proceeds faster in laboratory animals than in humans, 37 but quite surprisingly, differences in wound healing have even been found between horses and ponies. 79,80 Different animal species have been used as models of wound healing in humans, and some of the data can be adopted as a reference for the age determination of wounds involving the same species.…”

“…9,53,79,80 As an example, it has been shown that healing starts earlier and proceeds faster in laboratory animals than in humans, 37 but quite surprisingly, differences in wound healing have even been found between horses and ponies. 79,80 Different animal species have been used as models of wound healing in humans, and some of the data can be adopted as a reference for the age determination of wounds involving the same species. Nonetheless, the lack of precise data that can be used to support the conclusions is a professional challenge for the veterinary forensic pathologist who faces criminal cases in which the interpretation needs to be made ''beyond any reasonable doubt'' rather than ''on the balance of probabilities.''…”

Emprego de membrana de quitosana em feridas cutâneas induzidas experimentalmente em equinos

“…Os equinos apresentam complicações na cicatrização de feridas em regiões distais de membros, quando comparadas às feridas de tronco, e isso se deve a uma longa fase reparatória, caracterizada por grande retração da ferida, baixas taxas de epitelização e cessação precoce da contração da ferida (JACOBS et al, 1984;WILMINK et al, 1999). Os equinos possuem precursores dermais e subcutâneos próprios que predispõem a formação de tecido de granulação exuberante (CHVAPIL et al, 1979), atrasando a cicatrização por inibição da contração da ferida e subsequente epitelização, podendo resultar em grandes áreas ulceradas (JACOBS et al, 1984).…”

Treatment of a circumferential strangulation wound of the crural region involving all extensor tendons in a foal

“…Im Gewebe führen hypoxische Zustände schließlich zum generalisierten Zelltod. Selbst wenn es zu einer Reperfusion kommen sollte, bilden sich reaktive Sauerstoffradikale, die in Verbindung mit der ischämisch bedingten Energieunterversorgung der Zelle zu einer Reperfusionsnekrose in den betroffenen Körperabschnitten führen (Mosier 2009 Epithelisierung beträgt an der Gliedmaße nur 0,09 mm/Tag, am Rumpf dagegen 0,2 mm/Tag (Theoret 2008b (Wilmink et al 1999a(Wilmink et al und 1999b. Sie bilden mehr Myofibroblasten und zeigen daher eine wesentlich ausgeprägtere Wundkontraktion (Wilmink und van Weeren 2005).…”

“…Sie bilden mehr Myofibroblasten und zeigen daher eine wesentlich ausgeprägtere Wundkontraktion (Wilmink und van Weeren 2005). Die Wundheilung läuft bei ihnen schneller ab, und es treten wesentlich seltener Wundheilungsstörungen auf (Wilmink et al 1999a, Wilmink et al 2002 …”