Hydropenia in cat and dog. Ability of the cat to meet its water requirements solely from a diet of fish or meat

Abstract

The physiology of hydropenia was studied in cats and dogs placed on three regimens: 1) no water—no food; 2) water ad libitum—no food; and 3) no water—food. Animals deprived of water and food show elevations in plasma sodium, chloride, osmotic pressure and total solids, with progressive hydropenia. Tap water ad libitum prevents these changes in fasting and promotes slight decreases in plasma osmotic pressure; it also sustains life well beyond the period endured by animals with no access to fluid. That cats with no drinking fluid are able to maintain themselves well for long or indefinite periods on diets of cod, salmon and beefsteak, and are unable to do so on partly desiccated salmon and beef, is generally predictable by metabolic calculations and confirmed by measurements. The significance of these facts for the water metabolism of marine mammals which may not drink is broached.