COMPARE THE DOG'S DAILY WATER CONSUMPTION WITH NORMAL VALUES
If your dog is drinking a large amount of water, but not urinating frequently, then the excessive intake may be only a perceived problem. The average water intake and urine output for normal dogs is about 30mls/pound/24 hours, which is about one ounce/pound/day or 100 ounces (approximately 12 cups/day) for your 100-pound dog. To find out if the water consumption is indeed excessive, you will need to determine your dog’s daily average water consumption.
Concurrently, your veterinarian may assess the urine produced with a urinalysis. The concentration of the urine will reflect directly and indirectly the water intake. If your dog makes concentrated or moderately concentrated urine, then your pet’s water consumption reflects what his needs are. Dogs eating dry food or living in a heated environment may have increased water requirements that are not pathologic.
If the urine is poorly concentrated, and if the dog is drinking significantly more than the calculated amount, then your veterinarian will need to assess whether the increased thirst is organic or behavioral in origin. Kidney failure, liver disease, and some endocrine disorders often cause increased thirst. Kidney failure is very common in older dogs; usually the first signs are increased thirst and urination. Increased thirst can also be behavioral, secondary to attention seeking, boredom, pain or unknown causes.
Please discuss this with your veterinarian; provide him or her with the information on how much water your dog drinks daily. This should be very helpful.