Urinary production in the healthy horse and in horses deprived of feed and water.

This research focused on studying the amount of urine produced by healthy horses in comparison to horses that have been deprived of food and water for several days, taking into account the environmental temperature.

Research Context and Methodology

• The study used a sample of 11 healthy horses for the experiments. The horses were provided alfalfa hay and had unrestricted access to salt.
• The environmental condition under consideration was periods of high temperature.
• The urinary output of each horse was recorded on a daily basis over a 24 hour period under two circumstances. First, when they were healthy and had access to feed and water, and second, for periods of 24, 48 and 72 hours when they were deprived of feed and water.

Research Findings

• The average daily urinary volume in healthy conditions (with access to feed and water) was 15.6 liters, characterized by a mean specific gravity of 1.028 and urinary flow rate of 1.24 ml/kg/hr.
• Under conditions of feed and water deprivation, the average urine production significantly reduced to 6.3 liters during the first day, 3.2 liters on the second day, and further to 3.0 liters by the third day.
• Interestingly, the amount of electrolytes excreted in the urine decreased during this deprivation period, even though the concentration of major ions such as sodium actually increased. This suggests that the body of the horse may be conserving water and adjusting electrolyte balance under conditions of deprivation.
• Moreover, the study noted a strong correlation between the excretion of principal cations (sodium and potassium) and the main anion (chloride) in the urine.
• However, under conditions of feed and water deprivation, urinary excretion of water and electrolytes seemed to level off and stabilize after the initial 48 hours.

Conclusion

• This research gives insight into the physiology of horses and how they adapt to periods of feed and water deprivation. In coping with such conditions, the body of the horse was observed to regulate the amount and nature of constituents in the urine, which appears to stabilize after 48 hours of deprivation. This shows a remarkable ability of horses to conserve water and maintain electrolyte balance under stress conditions.