I don't feel safe ever placing a dog in a home with a bite above a "level 3" on Ian Dunbar's bite scale. At that point, the dog has demonstrated a lack of bite inhibition that can't realistically be trained late in life. Fortunately, most bites are a level 1 or 2!
Once you identify the objective severity of the bite, you can identify the potential cause. For bites below a level 3, we're looking for "Instrumental Aggression." Instrumental aggression serves a function, it's inhibited, and it has a logical and consistent sequence of events. (For example: Stare, growl, snap, bite.) As a dog trainer, dogs who demonstrate 'instrumental aggression' are simple to both treat and manage the 'aggressive' behavior in the meantime. Most cases of instrumental aggression are secretly just fearful dogs. These cases will need additional support from your behavior team both during and following the adoption process, but can be extremely rewarding for everyone involved.
If we see a bite above a level 3 on the bite scale, we're probably looking at 'Impulsive Aggression.' These cases are untreatable by most reasonable standards. These cases don't have a logical sequence of behaviors leading up to the bite, they're disproportionate to the situation, they don't necessarily serve a purpose, and they increase in severity/frequency over time. These dogs unfortunately will likely be euthanized, as there's no reasonable way to manage their aggressive behavior in a home environment. Luckily, these cases only make up 1-2% of your total intakes.
Hope this helps!
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