Primary polydipsia symptoms, such as delusions involving fluid intake or other unusual behaviours. Primary polydipsia may have physiological causes, such as autoimmune hepatitis. Since primary polydipsia is a diagnosis of exclusion, the diagnosis may be made for patients who have medically unexplained excessive thirst, and this is sometimes incorrectly referred to as "psychogenic" rather than "primary" polydipsia. As a diagnosis of exclusion, a diagnosis of primary polydipsia may be the result of elimination of the possibility of diseases causing similar signs and symptoms, such as diabetes insipidus. Diagnosis may be complicated by the fact that chronic and extreme compulsive drinking may impair
Polydipsia in birds chickens (broilers), subjected routinely to chronic food restriction, show increased drinking after a single daily meal along with other oral stereotypies. Expression of these activities is correlated positively with the level of restriction imposed, and is thought to be controlled mainly by central dopaminergic mechanisms. Under experimental conditions where birds receive reinforcements on a strict schedule, for example receiving one pellet of food each minute often indicated by a tone or other stimulus, the birds may develop polydipsia. Under these conditions it is called schedule induced polydipsia or sometimes, adjunctive drinking. Some strains of hens are polydipsic, drinking almost twice