Changes in behavior are frequently the earliest clinical signs of pathology. A dog that suddenly becomes aggressive may not have a "behavior problem"—it may be in pain due to arthritis or a tooth abscess. A cat that stops using the litter box may not be "spiteful," but could be suffering from a urinary tract infection or kidney stones.
In the past, vets treated the body and trainers handled the "attitude." Today, we know they are inseparable. zoofilia abotonada anal con perro work