Drinking and urinating more than normal
The main causes of horses drinking and urinating excessively are kidney disease (uncommon in horses), cushing’s (see section on cushing’s), psychogenic (the horse is simply drinking excessively without any underlying problem) or hypercalcaemia (high calcium levels caused by a malignant tumour).
Diagnosis
The water intake of the horse must be accurately documented and a sample of urine analysed.