APPROACHES TO WOUND CLOSURE

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A

B

Figure 4.11. Same horse as in Figure 4.4. (a) The wound 2.5 months post injury is healing by second intention. No treatment was
being administered at this time. (b) The wound 4 months post injury had almost completely healed and the horse had resumed its
intended function.

When the upper limb (just above the hock or carpus) is injured and second intention healing has been

selected, the wound should be supported with bandages and cleansed frequently until granulation tissue
forms.

Wounds of the distal limb (carpus or tarsus and below) suffering large tissue defi cits present a special

problem with the formation of exuberant granulation tissue. Studies show that horses have the ability to form
granulation tissue very rapidly when compared to laboratory animals.

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Other factors that may contribute to

the formation of exuberant granulation tissue include increased movement, lack of soft tissue covering, exces-
sive contamination, and reduced blood supply to the distal extremities. Importantly, treatment should be aimed
at prevention of the formation of exuberant granulation tissue. For more information regarding the development
and treatment of exuberant granulation tissue, see chapters 1 and 8.

Wounds of the upper extremities (proximal antebrachium and proximal crus), body, and neck regions heal

effectively by second intention. Usually a good functional and cosmetic end result is achieved (Figures 4.11a,b).
Conversely, large full-thickness wounds involving the distal extremity heal very slowly, and ultimately are
covered by a thin layer of new epithelium overlying a bed of scar tissue. Typically, the epithelial covering is
easily damaged and lacks or develops sparse adnexa (hair follicles, sebaceous and sweat glands) (Figures 4.12
and 8.9b). In these, skin grafting is recommended to improve the appearance and strength of the scar tissue.
For more information regarding skin grafting, see chapter 11.