Psychiatry is a specialized branch of medicine that studies behavioural disorders in humans and animals. In dogs and cats, behavioural problems are analogous to human psychiatric diseases, with the most common psychopathologies addressed being generalized anxiety disorder, obsessive compulsive disorder, separation anxiety and post-traumatic stress disorder. The level of bizarre behaviours displayed by the pets varies due to a variety of factors such as hereditary, prenatal dam modification and events during their neonatal and socializing phase. The behavioural changes recorded in dogs and cats include trembling, vocalizing, urinating, soiling, defecating, salivating, hiding, destructiveness, aggression, fear and obsessive behaviours. It is critical to remember that other medical complications, that can produce similar behavioural changes, must be addressed for the animal’s specific therapy. For the treatment of behavioural disorders in pets, different therapeutic agents (like Tricyclic antidepressants, selective serotonin reuptake inhibitors, benzodiazepines and a typical antidepressants) are used together with the behavioural modification strategies.