Wound Repair: What You Need to Know
October 23, 2012
Your pet is a special part of your life. Unfortunately, accidents do happen. Wound repair surgery is not just one type of surgery – many different techniques may be called upon to deal with different types of wounds. Some wounds are shallow and jagged, others deep and sharp, some clean, some are very dirty. Wound closure by surgery is usually done in the first 12 hours post-injury since after that time, so many bacteria may have entered the deep wound, even sterile flushes may not provide enough cleansing, and repair breakdown and infection, or even an abscess may occur.
Some wounds require multiple surgeries to repair them, and skin grafting may be required if there are large defects. Location of the wound on the body also influences the surgical repair since places that are under tension during movement or have no extra skin to pull together are difficult to repair. For example, wounds on the ends of the limbs or tail may be difficult to close if there is a gap since there is not any extra skin here to work with.
Some common wounds requiring surgery:
Grooming clipper or scissors
Puncture from foreign material such as thorns, nails, sticks
Laceration from sharp objects such as glass, wood, or metal
Animal bites (dog, cat, coyote)
When surgery is performed, a local or regional block may be used to numb the area, but since we cannot just tell our furry friends to hold still, many repairs require a general anesthetic be administered for the operation to be done safely.
As with any other surgery, the skin area is shaved and scrubbed to kill germs. Many times there is foreign material such as gravel, hair, or even pieces of tooth present in the wound, so careful cleaning is required. Puncture wounds do not look as bad from the outside, but are the most difficult to clean since they are narrow and and foreign material can be pushed deep into the tissues but hard to see or feel.
A sterile drape is placed over the surgical field and the surgeon will carefully remove (debride) any devitalized tissues, flush the wound with sterile saline, and will pull together any gaps so to eliminate dead (empty) space. It may be impossible to pull things together if the tissue inside is badly torn or some is missing. If there are gaps, or the tissues were badly contaminated, a surgical drain may be placed.
A drain can be active or passive. In an active drain a little pump puts suction on the tube and it will draw fluid out and into a reservoir outside the body. A passive drain “wicks” the fluid out by leaving a small pathway to the outside along a soft tube. Drains are widely used when an abscess has formed. Drains require regular care at home and often stay in for 3-5 days after the surgical repair. Cat bite wounds frequently develop cellulitis or abscesses. Cellulitis is a tissue infection without a pus pocket (the latter is found in an abscess).
If a wound has left a defect in the skin for closure, a skin plasty technique may be used. A plasty uses the skin around the wound, released from its anchor with carefully placed incisions so the surgeon can draw the now loosened skin over the defect.
In some wounds, the skin may die off if the circulation that nourishes it is lost due to blood vessel damage. This is called necrosis and the dead skin will need to be completely removed to facilitate healing.
Unfortunately, our pets cannot be told to leave their repaired wound alone, and so may be sent home with a cone or Elizabethan collar to be worn until healing is well underway. Otherwise, they may pull their stitches out! Some patients may not like “cone heads”, but they may be necessary for a while. Another way to protect the area is to bandage it. Not all animals will tolerate bandages well, and not all wounds should (or can) be bandage so a cone may be the only choice. Spraying around the wound or bandage with bitter solution can help discourage licking and chewing at the area. After a few days of healing, skin stitches may become itchy, so protection of the area may need to extend for a week or two.
Wound repair surgery most frequently requires a general anesthetic, and so preparation of the pet may include pre-op bloodwork, ECG, sometimes X-Rays, and will include a pre-op check up. Pain medicine will be started soon after the pet arrives to relieve any suffering. Very severe wounds can be associated with complications such as shock, so treatment plan and length of stay varies a lot, depending on the wounds, and overall animal status.