It is usually triggered by fleeing from the dog, which then reverts to the predatory behavior of chasing, biting, and potentially killing its prey for food. Caused by seizure-like brain disorders, this type of aggression may be directed indiscriminately toward anyone or anything, and accounts for only a small fraction of attacks by aggressive dogs . The following symptoms are merely indicators of aggression. None of these symptoms, occurring individually, should be ignored, and a combination of several of these behaviors can be an indicator of a serious aggressive behavior problem. These include play growling, growling while in a crate, fence fighting with other dogs, barking or lunging at other dogs while on a leash, or growling at another dog over food or a bone.
True aggression arises from the dog's intention to intimidate or to inflict harm.
The distinction is best made through careful observation of the dog's behavior when it is unrestrained and permitted to exercise its will. For example, if the dog bites or dominantly pins another dog while displaying these behaviors, it is probably aggressive. If not, the dog is simply expressing an opinion, with no intention of causing harm. Labrador Retrievers are not exempt from any of these types of aggressive behavior. In fact, aggression in Labs is often overlooked because most of their behavior seems noncompetitive and easygoing.