: A sudden increase in aggression, hiding, or vocalization is often the first sign of underlying pain, such as arthritis, dental disease, or internal discomfort.
Conditions like hypothyroidism in dogs or hyperthyroidism in cats directly alter brain chemistry, leading to sudden anxiety, irritability, or hyperactivity. Fear-Free Veterinary Care: Revolutionizing the Clinic Free Zoophilia Forum
Conditions like separation anxiety, noise phobia, and obsessive-compulsive disorder (such as tail chasing in Bull Terriers or acral lick dermatitis in Dobermans) are often driven by imbalances in serotonin and dopamine. : A sudden increase in aggression, hiding, or