A dog bite can break a bone, though this outcome depends on the dog’s size and the specific area of the body bitten. The jaw strength of certain breeds can generate forces far exceeding the pressure needed to fracture smaller bones in the human body. Understanding the mechanics of a dog’s bite and which parts of the body are most vulnerable helps clarify the risk of skeletal injury. This information is crucial for assessing the severity of a bite and knowing how to respond if a fracture is suspected.
Understanding the Physical Forces
The force a dog can exert with its jaws is the primary factor in determining the potential for a bone fracture. This force is often measured in pounds per square inch (PSI). While the average human bite registers around 120 to 140 PSI, large, powerful breeds can generate hundreds of PSI, with some reaching over 700 PSI, a pressure that can easily compromise bone integrity.
A dog bite causes skeletal damage through two distinct mechanisms: puncture and crushing. The sharp, pointed canine teeth are responsible for deep puncture wounds, which can pierce soft tissue and chip small, thin bones. The flat, strong molars create a crushing force, capable of causing comminuted fractures where the bone shatters into multiple pieces.
The structure of the dog’s skull and the powerful masticatory muscles contribute to this crushing capacity. When a dog bites down and holds or shakes, the concentrated force on a small area of bone can exceed its yield strength, resulting in a fracture.
Vulnerability and Location Factors
The likelihood of a bone breaking is highly dependent on the victim’s underlying bone health and the anatomical location of the bite. Children are significantly more susceptible to fractures and crushing injuries because their bones are smaller, less dense, and still developing. Older adults and individuals with conditions like osteoporosis also have reduced bone mass, making them vulnerable to fractures.
Fractures are most frequently observed in parts of the body containing small, delicate bones or those commonly used to defend during an attack. The hands and fingers are common sites for fractures, as people instinctively raise their arms to block their face and torso. These small bones can be easily crushed by a dog’s powerful bite, often requiring complex surgical repair.
The feet, toes, and facial bones are also areas where fractures often occur due to their lack of protective muscle and fat layers. The long bones of the arms and legs, such as the femur or tibia, are much stronger and are rarely fractured by the bite force alone. In these larger limbs, fractures are more likely to result from the victim being knocked down or the dog violently shaking the limb.
Immediate Steps After Suspected Bone Injury
If a dog bite has occurred and a bone fracture is suspected, the immediate response must focus on safety and preparing for urgent medical care. Signs of a fracture include severe, persistent pain, an inability to move the injured limb, swelling, or a visible deformity. If the wound is deep or exposed bone is visible, seek emergency medical help immediately.
The first step is to control any bleeding by applying gentle, direct pressure to the wound with a clean cloth or sterile dressing. If the injury is to a limb, gently elevate the area above heart level to reduce blood flow and swelling. Do not attempt to clean or manipulate a wound that may have a bone fracture, as this could cause further damage.
Gently immobilize the injured area to prevent movement, using a splint or sling if available and the limb is not visibly deformed. Immediate medical evaluation is required for all dog bites that break the skin, due to the high risk of deep infection from bacteria. Medical professionals will clean the wound, assess the need for tetanus prophylaxis, and use X-rays to diagnose the extent of the bone damage.