Nearly all animal wounds are contaminated with dirt and bacteria. Proper care and handling will reduce the risk of tetanus and prevent many infections. Before handling a wound, make sure your hands and instruments are clean. The five steps in wound care are:
- Skin preparation
- Wound irrigation
- Wound closure
Remove the original pressure dressing and cleanse the area around the wound with a surgical scrub solution. The most commonly used solutions are Betadine (povidone-iodine) and Nolvasan (chlorhexidine diacetate). Both products are extremely irritating to exposed tissue in the concentrations provided in the stock solutions (Betadine 10 percent, chlorhexidine 2 percent), so be very careful that the solution does not get in the wound while scrubbing the skin around it. Dilute the solution to weak tea color for Betadine or pale blue color for Nolvasan.
Three-percent hydrogen peroxide, often recommended as a wound cleanser, has little value as an antiseptic and is extremely toxic to tissues.
After the scrub, start at the edges of the wound and clip the dog’s coat back far enough to prevent any long hairs from getting into the wound.
The purpose of irrigation is to remove dirt and bacteria. The gentlest and most effective method of wound cleansing is by lavage, which involves irrigating the wound with large amounts of fluid until the tissues are clean and glistening. Do not vigorously cleanse the wound using a brush or gauze pad because this causes bleeding and traumatizes the exposed tissue.
Tap water is an acceptable and convenient irrigating solution. Tap water has a negligible bacterial count and is known to cause less tissue reaction than sterile or distilled water.
If possible, add chlorhexidine solution or Betadine solution to the tap water for antibacterial activity. Chlorhexidine has the greater residual antiseptic effect, but either antiseptic solution (not soap solutions) is satisfactory when correctly diluted. To dilute chlorhexidine, add 25 ml of the 2 percent stock solution to 2 quarts of water (2l), making a 0.05 percent irrigating solution. To dilute Betadine, add 10 ml of the 10 percent stock solution to 2 quarts of water to make a 0.2 percent irrigating solution.
The effectiveness of the irrigation is related to the volume and pressure of the fluid used. A bulb syringe is a low-pressure system. It is least effective and requires more fluid to achieve satisfactory irrigation. A large plastic syringe removes a moderate amount of dirt and bacteria. A home Water Pik unit (used by people to clean their teeth) or a commercial lavage unit that provides a high-pressure stream of fluid is the most effective.
A garden hose with a pressure nozzle for the initial lavage, or a kitchen sink spray unit, followed by one of the methods just described to deliver the anti- septic, is a good alternative. You want to flush and clean the wound, not force dirt deeper into the tissues. Angle your flow of liquid to accomplish that and let the fluid pool to bring debris to the surface.
Debridement means removing dying tissue and any remaining foreign matter using tissue forceps (tweezers) and scissors or a scalpel. Debridement requires experience to determine the difference between normal and devitalized tissue, and instruments to control hemorrhage and close the wound. Accordingly, wounds that require debridement and closure should be treated by a veterinarian.
Fresh lacerations on the lips, face, eyelids, and ears are best sutured or stapled to prevent infection, minimize scarring, and speed recovery. Lacerations longer than half an inch (1.25 cm) on the body and extremities probably should be closed, but small lacerations may not need to be. Small V-shaped lacerations heal best if they are closed.
Wounds contaminated by dirt and debris are quite likely to become infected if closed at the time of injury. These wounds should be left open or sutured around a drain that can be used for through-and-through irrigation. Similarly, wounds older than 12 hours should not be closed without drainage. Suturing or stapling should be avoided if the wound appears to be infected (is red, swollen, or has a surface discharge).
Your veterinarian may decide to close a wound that has been left open for several days and has developed a bed of clean tissue. Wounds that are clean after several days are resistant to infection and usually can be closed with impunity. Suturing such a wound is called delayed primary closure.
The length of time sutures or staples should remain in place depends on the wound’s location and other characteristics. Most sutures and staples can be removed after 10 to 14 days.
Puncture wounds are caused by bites and pointed objects. Animal bites, in particular, are heavily contaminated with bacteria. Bleeding may occur. There may also be bruising, particularly if the dog was picked up in the teeth of a bigger dog and shaken. Puncture wounds are often concealed by the dog’s coat and may be easily overlooked until an abscess develops a few days later.
Treatment of a puncture wound requires a veterinarian. It involves surgically enlarging the skin opening to provide drainage, after which the area is irrigated with a dilute antiseptic surgical solution. These wounds should not be closed. If there is a large, open wound area, parts of the wound may be sutured with a drain left in place to allow air to get in and discharge to drainage. With all animal bites, keep in mind the possibility of rabies. If it is a bite wound from an unknown animal, a rabies booster may be needed.
Antibiotics are frequently prescribed for bite wounds and wounds that are heavily contaminated, such as puncture wounds.
Small open wounds can be treated at home without sutures or staples. Medicate twice a day with a topical antibiotic ointment such as triple antibiotic. The wound can be left open or covered with a dressing. Make sure the dog is not constantly licking it. You can cover the area with a sock or a T-shirt to keep the dog away from the wound.
Infected wounds that are draining pus require the application of moist sterile compresses. A number of topical antiseptics are effective in treating superficial wound infections. They include chlorhexidine and Betadine (diluted as described in Wound Irrigation), Furacin (both the topical cream and 0.2 percent solution), 1 percent Silvadene cream, and topical antibiotics containing bacitracin, neomycin, and polymyxin B (triple antibiotic). Apply the topical antibiotic directly to the wound or place it first on a gauze pad. Change the dressing once or twice a day to facilitate pus drainage.