PATTERN OF NORMAL WATER DRINKING IN DOGS

Abstract

A dog with exteriorized bladder stood in a stall hung from a Sauter balance. Water losses were measured every 15 mins.; and water was drunk spontaneously from a pan kept before the dog. Losses were varied by heating the dog and by feeding at precise intervals. One signal that initiates drinking appears to be a deficit of body water relative to other bodily components. Whenever the body is depleted by about 1/2% of the body wt., water is drunk. The amt. drunk is accurately proportioned to the body''s deficit at each draft, although no absorption has time to occur before drinking ceases. Drafts are ordinarily taken about 5 times daily. Body wt. is only a rough criteron of water balance, since addition of food and loss of catabolic products complicate its relations.