Dog Bite Wounds Are Like Icebergs

One of the more common reasons we have dogs visit our urgent care is to have a dog bite wound addressed. Whether it was from an over-exuberant play session, fear reactivity, or an aggressive interaction, dog bite wounds have some common pitfalls and occurrences.

Dogs have incredibly strong jaws: the highest recorded strength is 743 pounds per square inch (PSI). For contrast, a human bite is about 150-200 PSI. When bites occur, not only are punctures or lacerations created, but often the bitten pet moves. This results in deeper trauma to the underlying fat, connective tissue, and muscle. Finally, there is often some degree of a crush injury to the surrounding tissues, and these crush injuries may take several days to become evident. This means that a scratch or surface wound may be hiding a more serious or complex wound under the surface. Any time a dog is bitten by another dog, they need immediate veterinary evaluation.

We saw Ranger, an 8.5-year-old mixed breed dog, shortly after an unfortunate encounter with an off-leash dog. On arrival, Ranger was very stable but had puncture wounds evident along his jawline and on the side of his chest.

After discussing the complexity of bite wounds, Ranger’s family approved having him sedated so that his wounds could be addressed without distress to him. His wounds were thoroughly cleaned, sutured closed (where appropriate), and he was started on oral antibiotics and pain control.

Unfortunately, Ranger’s wounds did not improve as we had hoped. Three days after his visit, the wound on his side became more red, hot, swollen, painful, and his appetite had decreased. While there wasn’t obvious overlying tissue damage, all of these signs indicated his wounds deserved another assessment. Ranger was sedated again for wound evaluation, which showed that the fatty tissues under the original wound had experienced a crushing injury, and were losing blood supply (this is called becoming non-viable). This inflamed and dying fatty tissue was the main source of Ranger’s persistent discomfort. There was also a small portion of skin that had become non-viable as well. All the affected tissue was surgically excised (removed), and the wound was thoroughly flushed.

When a large amount of tissue is removed, the body will try to fill up this new “empty” space with fluid. This fluid accumulation is commonly called a seroma, but when an infection is present, bacteria can live within this fluid and form an abscess. To help mitigate this potential complication, a specialized drain was placed, called a Jackson-Pratt drain, or JP drain, for short. These are the same devices used in humans after certain procedures, such as abdominal surgery or breast reduction. These drains allow for continuous drainage of fluid while helping to keep the original wound as clean as possible by preventing entry of environmental bacteria. These drains require extra management once a pet goes home, but are typically very well tolerated.

The tube seen exiting the wound at the top is attached to a suction bulb, similar to a turkey baster bulb. This bulb is emptied several times a day at home as needed. After 3-5 days, the drain tube is easily removed (no sedation is needed), allowing the wound to continue healing. After Ranger’s JP drain was removed, he continued to do well at home with his family’s diligent care, and his sutures were removed 14 days after his surgery and he fully recovered.

Ranger’s case highlights some of the interventions that may be necessary when treating dog bite wounds. Any dog bite should be evaluated as soon as possible, as antibiotics and pain control are often required. Even with surgical intervention, these wounds may not heal as perfectly as we would hope, and in some cases, a secondary procedure is needed to support proper healing. Thanks to Ranger’s attentive family and timely care, his wounds healed well, and he’s back to enjoying belly rubs and long walks. We were so happy to help Ranger return to doing what he loves most—spending time with his family.