Working dogs can easily pick up cuts and scrapes in the field, and Amira Nasim-Hopfer details how to manage the types of wound your dog might encounter.
A common skin laceration can often look dramatic, but if presented within the first six hours (“the golden period”), when the wound is considered contaminated but not infected, then they usually heal uneventfully. Figures one and two show two injuries sustained from a barbed wire. These rarely bleed much, providing a major blood vessel is not involved, and often go unnoticed. If a would like this is bleeding, providing pressure with a clean towel may help to control it during the time it takes to bring the dog to the vet.
On arrival, your vet will assess the wound, and this initial evaluation must include a thorough assessment of the whole animal. Many wounds that we see in practice are caused by traumatic injuries and subsequently there may be other, more life-threatening conditions present, such as internal bleeding or a ruptured bladder. The fundamental considerations when assessing open wounds are: the level and type of bacterial contamination, the blood supply, the viability of the tissue and the type involved.
Bite wounds have a great potential for delayed infection and wounds breaking open, not only due to the contamination by the bacteria of the oral cavity, but also due to the crush and penetrating injuries sustained by the patient. There are several factors which determine the outcome of the wound. A blood supply to the wound is vital. The blood supply provides anti-inflammatory cells and growth promoters. Road traffic accidents are usually grossly contaminated and may have foreign material ground into the bone and soft tissues. Any foreign material has to be removed before the wound will be able to heal. If a foreign body is missed, then an abscess, a sinus tract, long-term wound infection and prolonged healing times may result.
There are many bacterial species that may be found in wounds. Bite wounds, for example, are usually infected with Pasteurella species of bacteria and thus adequate antibiotics must be instigated. Your vet may choose to take a swab of the wound for bacterial culture and sensitivity testing, especially if the wound is showing signs of spread.
The aim of wound management is to optimise the conditions for healing, which will depend on the type of wound. If the wound is relatively clean and fresh, then it may simply be stitched under general anaesthetic (as shown in figures three and four), and normal healing can be complete within 10 days. If it is contaminated, then the wound may need to be debrided (scraped or cut clean) and closed at a later date once it is clean. The aim of debridement is to remove devitalised, contaminated or infected tissue and foreign material from the wound. Small wounds suspected to contain foreign bodies may need to be treated as open wounds (as in figure five). Regardless of how the wound is treated, the surrounding skin must be adequately clipped and cleaned with plenty of flushing to prevent further contamination. Surgical wound exploration may be warranted to allow better visualisation of local anatomy, which will be used to determine the best cause of treatment. For instance, a small cut above a joint could hide a deep puncture wound involving that joint, which would require more aggressive treatment.
So, if a wound is infected, contaminated or non-healing, the closure may be delayed and the wound managed as an open wound. If there is insufficient skin tissue available to allow reconstruction without tension, then open wound management will also need to be employed. Open wound management (figure six) involves selection of an appropriate dressing. For instance, an infected or contaminated wound will require a different type of wound dressing when compared to a healthy granulating wound. Some dressings are used for debridement (i.e. wet to dry dressings), whereas others are used to absorb fluid discharge or even promote healing. Ideally, the dressing should ensure a moist environment. There is a vast array of gels, ointments and creams available that can be applied between the wound and dressing. Careful selection is required, as some are used to draw out foreign objects like splinters, others are used to provide moisture to the wound, and some are cleansing.
To ensure the dressing stays in place, cotton wadding is used as a secondary bandage layer. It also provides some absorption as well as padding and support. A colourful self-adhesive wrap is then applied. Frequent bandage changes are necessary to prevent strike-through. If the wound is allowed to get too wet, then the wound and the surrounding skin can get macerated. Home bandage care is of fundamental importance. As an owner, you must ensure the bandage does not get wet. You should also check the bandage has not slipped and that it is not rubbing or compromising the blood supply. This is particular important with leg bandages. If an area of skin adjacent to a bandage feels warm or cold, or changes colour, then you must phone your vet immediately.
Static or non-healing wounds can be frustrating to all concerned. In such cases, it is important to try to establish the cause. The normal healing phase is delayed by anything that allows the inflammatory phase to persist, such as infection, foreign material, drying out of the wound and continuing tissue damage. Too much movement or friction by the bandage rubbing for example can also delay healing. These will all delay the granulation tissue formation, and hence healing. A swab for bacteriological culture and sensitivity, a biopsy of the wound or a general health check may be necessary. It is important to remember that tumours may appear as open wounds, depending on their location and stage of growth. Once the underlying cause is established, then treatment can be initiated. There are numerous sophisticated ways in dealing with complicated wounds. For instance, reconstructive surgery, flaps and skin grafts can provide full-thickness cover of wounds. Novel approaches include low-level laser irradiation, and negative pressure therapy. Vacuum-assisted closure (VAC), involves applying controlled subatmospheric pressure via an open-pore foam dressing. This has recently been shown to have promising results.
As wounds are frequently contaminated, antibiotics will be warranted, and in all injuries, it is important to provide pain relief. Dogs are often so good-natured and hard-working they can hide the fact that they are in pain. Some pain killers also have the added benefit of having an anti-inflammatory action.
If your dog sustains an injury, it is always easier to treat a wound sooner rather than later. Most wound complications are not life-threatening, but they do prolong periods of discomfort for the animal. When managing open wounds the aim is to allow the healing process to proceed normally or to enhance it, but in all cases quick medical attention is the best start to that process.