The role of body fluids on thermoregulation of one-humped camel to seasonal variations was studied in five 5-9 years old male one-humped camels. Changes in rectal temperature, respiration rate and pulse rate, body fluids, thyroid hormones, liver and kidney function tests, Hb, Ht plasma proteins (total proteins, albumin, globulin and A/G ratio), plasma electrolytes (Na and K) and plasma aldosterone concentration were determined during different seasons.

Results indicated that rectal temperature was significantly higher in summer than in winter which was accompanied with an insignificant increase in respiration and pulse rates and a significant decrease in T4. Total body water as percentage of body weight was significantly higher in summer than in winter due to significantly higher ECF, ICF, ISF and PV%. The higher body fluid content as percentage of body weight during summer was due to higher plasma K concentration, while plasma Na concentration decreased significantly during the hot season with no significant changes in plasma proteins between seasons. Spring values were close to those of winter, while those of autumn were close to summer values. As a result, plasma aldosterone concentration did not differ significantly between seasons to keep the high level of K in plasma which increased plasma osmotic pressure causing the higher plasma volume in summer. Plasma AST, ALT and creatinine did not differ significantly between seasons revealing no significant effect of hot climate on liver and kidney functions.

In conclusion, the increase in RT during hot season may be a water conservation mechanism by heat storage as indicated by insignificant changes in RR and high percentages of body fluids. Plasma proteins, Na and aldosterone had no significant roles in changes in body fluids between seasons while the significant increase in plasma volume during hot season was due to the increase in plasma K concentration.