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An Urban Experience
L. O’Dwyer1
1VetsNow, Anaesthesia & ECC, Manchester, United Kingdom
Louise O’Dwyer MBA BSc(Hons) VTS(Anesthesia&ECC) DipAVN(Medical & Surgical) RVN
Clinical Support Manager, VetsNow, Manchester, U.K.
Non-healing, or difficult to heal wounds in veterinary practice rarely pose an immediate risk to life, however they can result in prolonged periods of veterinary care which can be very costly to the owner, uncomfortable and stressful for the patient, and potentially may result in euthanasia, or limb amputation in some cases.
There are numerous underlying causes of non-healing wounds and these can generally be divided into wound factors, patient factors and surgeon factors.
Wound aetiology
Traumatic wounds may be more difficult to heal, dependent on the amount of damage caused to the surrounding skin. Also, when dealing with shearing injuries to the lower limbs, it is not uncommon for exposed bone to be present. Exposed bone is often encountered in distal limb degloving wounds and inhibits wound contraction and epithelialization. When allowed to heal by second intention, a bed of granulation tissue is required for second-intention healing to progress. During the wound healing process the majority of exposed bone with become covered with granulation tissue that arises from the viable periosteum or viable soft tissues adjacent to the bone surfaces, but there is always the risk of potential for osteomyelitis or sequestrum formation.
Wounds are commonly classed as clean, clean contaminated, contaminated and dirty. It is important
to determine the wound type from this perspective
order to plan wound management. Only clean or clean- contaminated wounds should be considered for closure, with all other wounds requiring at least a period of
open wound management to convert them to a clean- contaminated state, whereby they may be considered for closure.
When infection is present within a wound, this will cause inhibition of wound healing throughout all stages of the
wound healing process. In order to identify infection a deep tissue culture should be obtained, this is preferable to a surface swab, as surface contaminants do not truly reflect infection. Infection is thought to be present in around 3%
of all wounds at the time of suture removal, but infection rates are very variable, dependent on the degree of wound contamination. The aetiology of the wound also will affect the likelihood of infection occurring, with bite wounds having a high probability of infection due to the wound and its surrounding tissues creating the ideal environment for bacterial replication, along with poor drainage and a hypoxic environment. There are also surgical causes of infection
e.g. duration of the procedure, number of theatre staff, placement of surgical drains, suture material, underlying disease and the use of propofol, have all been associated with increased incidence in surgical site infections in veterinary patients. The following approach has been recommended when dealing with wound infection:
• Investigate and address any underlying causes or contributing factors, e.g. malnutrition, anaemia, systemic disease;
• Maintain an ‘open’ wound environment, while fully exploring any pockets between soft tissue planes using an aseptic technique;
• Debride necrotic, devitalised tissue;
• Ensure thorough lavage of the affected areas with sterile isotonic fluids is performed;
• Obtain deep tissue samples for aerobic and anaerobic bacteriological culture and sensitivity testing;
• Commence empirical antibiotics (which can be changed according to culture results);
• Use bandaging to help with debridement (e.g., wet-to- dry bandages, or antimicrobial dressings);
• Continue open wound management until infection is controlled
Wound location
Wounds over joints present a challenge to healing in that they are subject to tension, compression, or shearing forces. The desired result of wound healing is for the two sides of a wound to heal together. If they are exposed
to these forces, however, healing is impaired. Wounds over extension surfaces of joints (e.g. carpus, stifle)
are subject to tension when joint flexion pulls wound edges apart. Thus, meticulous closure is necessary. Wounds in the axillary and inguinal areas may result from forelimb entrapment in a collar, vehicular trauma, burns, neoplasia, and infections. A primary factor in
the impaired healing of such wounds is the shearing movement between the two wound surfaces as the animal ambulates. If such wounds have been present for a long period, it is possible that there may be infection

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