Aggression can be directed toward humans, other animals, or resources (food guarding). In the vast majority of cases, aggression is rooted in fear, anxiety, or underlying physical pain rather than a desire for dominance. Compulsive Disorders
In the wild, showing signs of pain or illness makes an animal a target for predators. Consequently, most species have evolved to hide their suffering. A cat suffering from severe osteoarthritis may not limp; instead, it might simply stop jumping onto its favorite window sill or become uncharacteristically aggressive when touched.