Salt (sodium) deficiency in dairy cattle: polyuria and polydipsia as prominent clinical features.

Polyuria in a herd of forty-five dairy cattle was the chief complaint in the first case. Polydipsia was the principle sign in a second case involving one dairy cow. Less conspicuous clinical findings included salt hunger, pica, weight loss and decreased milk production. Clinicopathologic investigation included monitoring the concentrations of sodium, potassium and chloiride in urine, parotid saliva and plasma. These analyses indicated a primary sodium deficiency which responded to sodium chloride ad libitum.