Excessive Water Consumption
Written by Dr. Cathy Zolicani
Diabetes Insipidus is fairly common in pigs. It can be caused for 3 possible reasons:
1. Psychogenic Water Consumption is a condition in which a pig develops the habit of drinking water. No one knows why. They will literally drink gallons at a time and will often stand and urinate while drinking. Treatment involves figuring out what their water needs are, and rationing that amount throughout the day while preventing them from tanking up. Many people elect to keep these pigs outside, where the excessive drinking and urinating is not a big problem.
2. Central Diabetes Insipidus where the pituitary/brain does not produce anti diuretic hormone (ADH) which causes the kidneys to retain water and concentrate the urine, so water needs in the body are reduced, and thirst is reduced.
3. Renal Diabetes Insipidus where the kidneys cannot respond to ADH, so they are not capable of concentrating the urine and retaining water. A 12 hour water withholding test is often not long enough in pigs because they have such huge bladders that the urine tested after 12 hr is still quite dilute. 24 hours is a more useful test, but the pig needs to be monitored by your vet in case dehydration occurs (this can be measured by weighing the pig frequently, as the pig dehydrates, they lose weight pretty rapidly). A desmopressin stimulation test can be done. This is giving the pig a test dose of synthetic ADH and then monitoring thirst and urine concentration. If this test is effective, then the pig can be treated with desmopressin at home on a regular basis. Renal based Diabetes Insipidus is the most rare and also most difficult to treat. Treatment involves balancing the water withholding against the very real risk of dehydration and electrolyte imbalance.