The most important functions of the kidneys are the regulation of the water balance, the excretion of urinary substances and the control of blood pressure, the electrolyte balance and thus also the acid-base balance.

They perform important tasks in the vitamin D metabolism and produce hormones such as erythropoietin, which is important for the formation of red blood cells. On the other hand, the kidneys and their functions are controlled by hormones. In order for the internal organs to be able to do their work, they depend on good blood circulation. This applies to the liver and lungs, it also applies to the kidneys, in which the blood pressure is higher than in the rest of the body so that the kidneys can perform their filtration work.

In older horses with circulatory problems, the kidneys can no longer perform to their full potential. That is why circulatory-regulating agents also have a kidney-supportive effect on these horses. The special thing about herbs is their aquatic effect. They do not simply dehydrate like chemical agents, which also flush out many electrolytes with the dehydration. The herbal remedies are now referred to as aquaretics to distinguish them from chemical diuretics. These special herbs increase the amount of urine without causing electrolyte losses. The only exception is sodium chloride, which can be easily balanced with salt licks.