Water Balance of the Camel

Abstract

Camels ( Camelus dromedarius) were exposed to prolonged periods of water deprivation during winter, spring and summer in the Sahara desert. Determinations were made of: weight changes, water and food intake, urine flow and concentrations, plasma concentrations, etc. It was found that the camel can tolerate a loss of water corresponding to 30% of its body weight even when exposed to the severe desert heat. Other mammals dehydrated in a hot environment may die from circulatory failure already when the water loss involves 12% of the body weight. Unlike many other mammals the camel does not lose its appetite when deprived of water but continues to eat normally until the desiccation becomes very severe. It has a low urine output (0.5–1 l/day when kept on a diet of dates and hay), a low water content in the feces, and, when dehydrated in the summer, a very low evaporative water loss. When offered water the camel drinks in 10 minutes enough water for complete rehydration. The longest period that we kept a camel on dry food without drinking water in the hot summer was 17 days. This camel was not working and it had its protective fur which decreased the heat gain from the environment. It is concluded that the ability of the camel to withstand prolonged dehydration is due to: a) tolerance to an extremely high degree of desiccation of the body and b) low overall water expenditure. Particularly effective as a water conserving mechanism is the low evaporative water loss during dehydration in the summer.

Physiological and behavioral responses to different watering intervals in lactating camels (Camelus dromedarius)

“…The results show that 1) lactating camels drank in anticipation of coming water deficits when water was offered at 4-or 8-day intervals but not enough to compensate body weight losses after 16 days water deprivation; 2) dehydrated lactating camels actively searched shade despite rectal temperature below 35°C; 3) plasma sodium concentration and osmolality increased after 4 days and, after 8 days, total plasma protein and vasopressin concentrations also increased; and 4) it took a long time for the lactating 4 812 16 1 4 812 16 1 4 812 16 1 4 812 camels to restore body fluid homeostasis after 16 days of water deprivation. Drinking huge amounts of water to rapidly replenish body weight loss in the camel was described about 50 years ago (36), and later the black Bedouin goat was shown to immediately drink amounts of water compensating a 40% loss of its body weight (38). Storage of the consumed water in the forestomach and gut, saliva buffering the forestomach contents, and the continuous exchange of electrolytes and water between gastrointestinal tract and blood plasma are important factors that explain the exceptional tolerance to water deprivation in camels and ruminants (40,41).…”

Climate influences thermal balance and water use in African and Asian elephants: physiology can predict drivers of elephant distribution

“…For example, many desert ungulates significantly reduce the rate of cutaneous and respiratory water loss when dehydrated (Maloiy, 1973;Schmidt-Nielsen et al, 1956), indicating that neuroendocrine integration is used to balance heat and water loss. We found that elephants are able to modulate water loss when evaporation potential is greatest (high WVPSD) (Fig.7).…”

Daily rhythms of physiological parameters in the dromedary camel under natural and laboratory conditions

“…The dromedary camel (Camelus dromedarius) is an important livestock species uniquely adapted to hot arid environments by its ability to reduce water loss through feces, urine, and evaporation (Bekele et al, 2013;Ben Goumi et al, 1993;Robertshaw and Zine-Filali, 1995;Schmidt-Nielsen et al, 1956). With increasing human population and inadequate food production in Africa and parts of Asia, it is important to develop semi-arid and arid rangelands through appropriate livestock production systems, and the camel is a natural choice (Schwartz and Dioli, 1992).…”