The Dog-Human 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 Human Bite Scale  (a HUMAN 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 victim pulling hand away, or gravity (little dog jumps, bites and drops to floor).
  • 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: Multiple-bite incident with at least two Level 3 or 4 bites or multiple-attack incident with at least one Level 3 or 4 bite in each.
  • Level 6: Victim dead.

Considerations that affect prognosis:

  • If the victim is very young or very old (thinner skin)
  • If the victim was wearing clothing
  • Location of bite on the body (thicker/thinner skin, next to bone, etc)
  • Medication the victim may be taking (blood thinners)
  • Was the victim close to the dog or did the dog have to travel to bite?
  • Did the dog stop biting once the victim backed off or vocalised?


  • Levels 0-1 = Good
  • Levels 2-3 = Lifelong management
  • Levels 4-6 = 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 4-6, 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.