Animals cannot verbally explain their pain. Instead, they communicate through a complex language of posture, facial expressions, and vocalizations.
Diseases affecting the hormonal systems often present as behavioral problems first. For example, a cat with hyperthyroidism may suddenly become hyperactive, vocalize excessively at night, or display uncharacteristic irritability. Conversely, a dog with hypothyroidism may present with sudden lethargy, cognitive decline, or fear-based aggression. Neurological and Cognitive Decline zooskoolcom top