Diseases affecting the endocrine system can radically alter behavior. For instance, hypothyroidism in dogs is frequently linked to sudden-onset aggression, anxiety, or lethargy. Conversely, hyperthyroidism in older cats often causes extreme irritability, pacing, and excessive vocalization. 4. Neurological Decline

Historically, veterinary curricula focused heavily on pathology, pharmacology, and surgery. Behavior was considered "soft science"—interesting but impractical. Animals, the thinking went, were driven by instinct and reflex. Pain was pain; fear was fear. What more was there to understand?

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

Historically, vets focused on clinical pathology—blood work, X-rays, and surgery. Today, the field of Veterinary Ethology