Understanding the Dunbar Dog Bite Scale
Posted on 8th of March, 2026
The Ian Dunbar Dog Bite Scale provides a clear and objective framework for measuring the level of injury a person may receive from a dog bite.
In fact, approximately 95% of incidents commonly described as “dog bites” result in minimal harm and are not caused by dangerous animals.
The scale was created by veterinarian and behaviourist Ian Dunbar to help trainers, veterinarians, and behaviour professionals discuss bite incidents in a more accurate and consistent way. Instead of relying on emotional or vague descriptions like “aggressive” or “dangerous,” the scale focuses on what actually happened and the level of injury involved.
This allows behaviour professionals to evaluate incidents more clearly and helps guardians better understand what their dog may have been communicating in that moment.
Levels of the Dunbar Dog Bite Scale
Level 1 — No Skin Contact
The dog shows warning behaviour such as growling, snapping, or air snapping, but no teeth make contact with skin.
What this usually means:
The dog is communicating discomfort or asking for space. Many dogs use these warnings specifically to avoid escalating a situation.
Level 2 — Teeth Touch Skin, No Puncture
Teeth make contact with the skin but do not puncture it. There may be redness or light bruising.
What this usually means:
The dog made contact but still showed excellent bite inhibition, meaning they controlled the pressure of their bite.
Level 3 — One to Four Shallow Punctures
One to four punctures from a single bite with puncture depth less than half the length of the dog’s canine teeth.
What this usually means:
The dog applied more pressure during a moment of stress or fear, but the bite still shows some degree of bite inhibition.
Level 4 — One to Four Deep Punctures
One to four punctures deeper than Level 3, indicating the dog applied significant pressure during the bite.
What this usually means:
The dog was highly stressed or reacting strongly in that moment, and the situation requires careful behavioural assessment with a certified professional such as a Veterinary Behaviourist.
Level 5 — Multiple Bites
Multiple Level 4 bites during one incident or repeated biting sequences.
What this usually means:
The dog’s behaviour requires immediate professional evaluation from a Veterinary Behaviourist and stringent management moving forward.
Level 6 — Fatal Bite
The most severe and extremely rare outcome.
Why This Scale Matters
One of the most important things the Dunbar Dog Bite Scale helps us understand is that not all bites are the same. Many incidents people refer to as a “bite” fall into the lower levels of the scale, where a dog may have made contact with teeth but caused little or no injury.
Dogs often communicate discomfort, stress, or fear long before causing serious harm.
Understanding the level of an incident helps professionals assess the situation more objectively and develop thoughtful training and management plans. Clear frameworks like the Dunbar Dog Bite Scale allow behaviour professionals to respond thoughtfully rather than emotionally when incidents occur.
When we understand what dogs are communicating and the level of injury involved, we can focus on prevention, better management, and skill-building that helps both guardians and dogs feel safer and more confident moving forward.