The Dog-Dog Bite Scale


Another part of risk assessment is to rate a dog’s bite history on a scale, which allows us to define a course of treatment and more importantly, a prognosis, for lack of a better term. 

Dog to Dog Bite Scale (a DOG is the victim)

  • Level 0: Warnings, air-snapping, muzzle punch, scratch with claws, but no contact with skin by teeth. 
  • Level 1: Teeth made contact with skin, but no puncture. May have superficial scratch or light bruising.
  • Level 2: One to four punctures from a single bite with no puncture deeper than half the length of the dog’s canine teeth. May have lacerations in a single direction, caused by owner pulling dog away.
  • Level 3: One to four punctures from a single bite with at least one puncture deeper than half the length of the dog’s canine teeth.
  • Level 4: One to four punctures from a single bite, may also have deep bruising around the wound (dog held on for N seconds and bore down), a hematoma, or lacerations in both directions (dog held on and shook its head from side to side).
  • Level 5: Internal damage, dog is in shock, dog is vomiting, uncomfortable, rib displacement, or affected gait. May or may not include punctures/lacerations.
  • Level 6: Multiple-bite incident with at least two Level 3,4, or 5 bites or multiple-attack incident with at least one Level 3,4, or 5 bite in each.
  • Level 7: Victim dead.

Considerations that affect prognosis:

  • If the victim is very young or very old (thinner skin)
  • If the victim was wearing clothing
  • The size difference between the aggressor and the victim
  • Location of bite on the body (thicker/thinner skin, next to bone, etc)
  • How much fur does the victim have? (Greyhound vs Samoyed)
  • Medication the victim may be taking (blood thinners)
  • Did the aggressor continue to bite once the victim retreated?


  • Levels 0-2 = Good
  • Levels 3-4 = Lifelong management
  • Levels 5-7 = Poor

We will dive deeper into Prognosis later in the program. If you are working through this program and your dog is at a level 5-6, you may want to skip to the Prognosis lesson and get in touch for a one-to-one consult to discuss safety protocols and ethical options. Check out the lesson on when to See Your Veterinarian or Veterinary Behaviourist as well.