Consider a 4-year-old Labrador Retriever presenting for growling at children.

A sudden onset of defensive aggression in a normally gentle dog often points to localized pain, such as osteoarthritis, dental disease, or spinal discomfort.

Veterinary behaviorists utilize medications such as Selective Serotonin Reuptake Inhibitors (SSRIs) like fluoxetine, or tricyclic antidepressants (TCAs) like clomipramine, to lower anxiety levels. By chemically reducing the panic response, the animal enters a cognitive state where they can successfully process desensitization and counter-conditioning therapies. The Role of Preventive Behavioral Medicine