317-488-5500 
A dog bite isn’t “minor” or “serious” based on how it looks. The Dunbar Dog Bite Scale, developed by veterinarian Dr. Ian Dunbar, gives an objective way to measure bite severity based on wound pathology – puncture depth, count, and bruising – rather than how the incident felt in the moment.
This page covers the official Ian Dunbar dog bite scale, an instant self-assessment tool, the dog psychology behind each level, and – for Indiana readers – exactly what state law requires next.
Contact a dog bite lawyer.
What Is the Dunbar Dog Bite Scale?
Created in the 1970s as a dog bite scale veterinary and behavioral tool, it uses physical evidence instead of eyewitness accounts, which are often inaccurate or emotionally charged. This makes the dog bite pressure scale useful to vets, trainers, animal control, insurers, and attorneys alike, since it produces a consistent rating regardless of who applies it.
The 6 Levels
Level 1 – Aggressive display, no contact. Snapping, lunging, growling; teeth never touch skin. A warning display, not an injury attempt. Prognosis: Excellent.
Level 2 – Contact, no puncture. Teeth touch skin but don’t puncture it. Possible minor nicks (under 0.1″) from lateral tooth movement, no vertical punctures. Real bite inhibition on display. Prognosis: Excellent.
Level 3 – Single bite, shallow punctures. 1–4 punctures, none deeper than half the canine tooth’s length. Possible single-direction lacerations from the victim or owner pulling away, or gravity. Prognosis: Fair to good, with conditions.
Level 4 – Single bite, deep punctures. 1–4 punctures, at least one deeper than half the canine’s length. Often deep bruising (dog held on and bore down) or bilateral lacerations (dog shook its head side to side). Prognosis: Poor.
Level 5 – Multiple Level-4 bites. At least two Level-4 bites in one incident, or one Level-4 bite per attack across multiple attacks. Prognosis: Grave.
Level 6 – Fatality. The victim is dead.
What the Damage Actually Means
When is a dog bite serious? No puncture (Levels 1–2): wash and monitor. Shallow puncture (Level 3): this is generally where what is considered a serious dog bite starts – professional cleaning, tetanus check, infection monitoring. Deep puncture or bruising (Level 4+): ER or urgent care, not home care.
How serious is a dog bite for someone on blood thinners? Anticoagulants (warfarin, apixaban, clopidogrel) reduce clotting, so even a Level 2–3 bite can bleed longer than expected. Seek evaluation regardless of Dunbar level and tell the clinician about the medication.
What damage can a dog bite have on the top of the hand? The dorsal hand has tendons, small joints, and vessels close to the surface with little cushioning – a Level 3–4 puncture here has a higher chance of reaching a tendon sheath or joint than the same depth elsewhere, which is why hand bites often go to a specialist.
How much damage does a dog bite to the forearm do? More muscle offers some buffer, but tendons controlling finger movement and major vessels run close to the surface near the wrist – deep punctures (Level 4+) can affect grip and tendon function.
Is it possible to get tendon damage from a dog bite that didn’t break the skin? Yes. Jaw pressure and twisting can cause blunt-force injury to a tendon or joint even at Level 2, with no visible puncture. Reduced range of motion or persistent swelling after a bite warrants a doctor’s visit even if the skin looks intact – Dunbar’s scale measures skin damage, not hidden soft-tissue injury.
Instant Bite Level Assessment
- Did teeth contact skin? No → Level 1. Yes → continue.
- Did teeth puncture skin? No → Level 2. Yes → continue.
- Punctures from a single bite? 1–4 → continue. More than 4, or this is at least a second Level-4 bite/attack → Level 5.
- Deepest puncture vs. canine tooth length? Under half → Level 3. Over half → continue.
- Did the dog hold and bear down, or shake its head side to side (deep bruising / two-directional lacerations)? Either way → Level 4, escalating toward Level 5 if this pattern repeats across multiple bites in the same incident.
(This guide is informational and doesn’t replace a veterinary behaviorist’s evaluation or medical assessment. Level 6 isn’t part of the flow – it applies only after a fatality.)
Why the Dog Bit
Bite Inhibition
Bite inhibition is a dog’s learned ability to control jaw force even when aroused or afraid, developed mainly through puppy play where littermates and people yelp at hard bites.
This is the key insight most bite scales skip: Levels 1–3 prove the dog has functional bite inhibition – it had the strength and opportunity to cause real damage and chose not to. Levels 4–6 mean that control has failed or never developed. That’s not always “meanness” – genetics, a poor socialization window, extreme fear, prey drive, or pain can all be behind it – but it’s why Level 4+ dogs carry a poor long-term prognosis: you can’t always teach an adult dog inhibition it never learned, and the retraining process itself carries risk.
Context of the Bite
The same Dunbar level can come from different causes, which changes both the plan and the prognosis:
- Fear-based: dog felt cornered or startled. Often responds well to distance and desensitization; even a Level 3 fear bite can carry a good prognosis.
- Play-related: common in puppies, usually Level 1–2 – a training gap, not aggression.
- Resource guarding / pain: defending food, space, or an injury; often responds to structured behavior work if caught early.
- Predatory: triggered by fast movement or high-pitched sounds, often from children or joggers. More dangerous, since it skips the usual growl-snap-bite warning sequence and can escalate to Level 4+ quickly.
Action Plans by Level
Levels 1–2 – Training-focused. These cover well over 99% of incidents; the dog isn’t dangerous, just fearful or under-trained. Use classical conditioning, Retreat-and-Treat and Come/Sit/Food Reward sequences, progressive desensitization, and bite-inhibition games. Hand-feed exclusively until resolved – every meal is a training rep.
Level 3 – Professional intervention. Fair-to-good prognosis, but only with full compliance, and DIY training is no longer enough.
- Contact a certified applied animal behaviorist (CAAB) or CDBC – not a general obedience trainer
- Interim safety: basket muzzle, separation from triggers, management tools (gates, crates)
- Document the incident – it matters for both training and, in Indiana, legal exposure (see below)
Levels 4–5 – Realistic risk assessment. Insufficient bite inhibition, genuinely dangerous, poor-to-grave prognosis, because adult retraining is hard and full compliance is rare. This is a materially higher risk with children in the home. If not rehoming or euthanizing, non-negotiable minimums: confinement to adults-only contact, a locked room or run whenever children/guests are present, muzzle outside the house (vet visits only), and reporting incidents to animal control or police.
At Level 5, the dog is inflicting mutilating injuries and isn’t safe around people under any realistic home setup. Given the poor quality of life in permanent solitary confinement, many veterinary behaviorists consider euthanasia the most humane option – a decision for a veterinary behaviorist, not a general vet or trainer.
Indiana Dog Bite Laws
Not legal advice – consult a licensed Indiana attorney for your specific situation.
Liability
Can someone sue me if a dog bite is not serious? Yes. Indiana’s common-law “one-bite rule” presumes a dog is safe until proven otherwise, which makes a first bite harder to win on negligence – but a minor bite isn’t automatically a bar to suit, especially if it caused real damages, the owner violated a leash ordinance, or the victim falls under strict liability (below). Once a dog has any documented bite – even Level 3 – the owner is generally considered on notice, making a second claim much easier to win.
Strict liability: Under IC § 15-20-1-3, an owner is liable regardless of history or awareness when a dog bites, without provocation, someone peaceably performing a duty required by state law, federal law, or postal regulations – covering postal carriers, police, and other government employees. Severity affects damages, not whether liability attaches.
Reporting
Physicians: Under IC § 35-47-7-4, a treating physician or hospital/surgical center administrator must report the bite to the Indiana Department of Health within 72 hours, orally or in writing.
Rabies quarantine: Even a Level 2–3 bite with broken skin triggers a mandatory 10-day quarantine to watch for rabies. Depending on vaccination status and the animal control officer’s assessment, this can be home confinement or confinement at a shelter, vet hospital, or licensed kennel.
Criminal Liability
Under IC § 15-20-1-4, an owner commits a Class C misdemeanor if they recklessly, knowingly, or intentionally fail to restrain the dog, it leaves the property, and it bites someone without provocation, causing injury. This escalates with history and severity:
- Class B misdemeanor – one prior unrelated conviction
- Class A misdemeanor – more than one prior conviction, or serious bodily injury (Level 4–5 territory)
- Level 6 felony – reckless violation resulting in death (Level 6)
- Level 5 felony – intentional/knowing violation resulting in death
In short: the higher the Dunbar level, the more likely a case moves from misdemeanor to felony, especially for repeat or reckless owners.
Indiana Resources and Contacts
State-Level
- Report an Animal Bite: https://www.in.gov/rabies/report-an-animal-bite/
- Rabies Information Home: https://www.in.gov/rabies/
- Indiana State Board of Animal Health: 317-544-2400
- Find your county health department: https://www.in.gov/health/lhd/local-health-department-map/
- Indiana State Dept. of Health: 317-233-1325
Indianapolis (Marion County)
- Indianapolis Animal Care Services (IACS): (317) 327-1397 – https://www.indy.gov/agency/animal-care-services
- Active attack / immediate threat: 911
Fort Wayne (Allen County)
- Fort Wayne Animal Care and Control: 260-427-1244
- Allen County Dept. of Health – Animal Bites: https://allencountyhealth.com/info-about/diseases-conditions/insect-animal-borne/animal-bites
Statute Text and Scale Source
- IC § 15-20-1-3 (Strict Liability): https://law.justia.com/codes/indiana/title-15/article-20/chapter-1/section-15-20-1-3/
- IC § 15-20-1-4 (Criminal Offense): https://law.justia.com/codes/indiana/title-15/article-20/chapter-1/section-15-20-1-4/
- IC § 35-47-7-4 (Physician Reporting): https://law.justia.com/codes/indiana/title-35/article-47/chapter-7/section-35-47-7-4/
- Dr. Ian Dunbar’s Dog Bite Scale (Official, via APDT): https://apdt.com/wp-content/uploads/2017/01/ian-dunbar-dog-bite-scale.pdf
If your county isn’t listed, contact your local health department or sheriff’s office – Indiana’s 92 counties each have their own animal control contact; the local health department map above is the fastest way to find yours.
Disclaimer
This page provides general educational information as of the current publication date. It is not a substitute for veterinary behavioral assessment, medical treatment, or legal advice. Laws and local ordinances vary by county and can change. If bitten, seek medical attention appropriate to the wound. If your dog has bitten someone, consult a certified veterinary behaviorist and a licensed Indiana attorney for guidance specific to your situation.
Call 317-488-5500 or complete a Free Case Evaluation form
