Excessive Thirst in a Dog: Oscar’s Increased Drinking and Diagnosis
Different environmental and physiological factors determine how much water your dog needs to drink on any given day.
Things that influence fluctuation in your dog’s water intake include:
- ambient temperature
- activity level
- type of diet
However, with all things being equal, if your dog starts drinking more than usual, you need to consider an underlying health problem. Illnesses that will make a dog thirstier include:
- hyperthermia
- diabetes
- kidney disease
- liver disease
- severe infections
- Cushing’s disease
- Addison’s disease
Further reading: Symptoms To Watch For In Your Dog: Excessive Drinking (Polydipsia)

Oscar’s story
Oscar was a 14-year-old Terrier and his mom’s heart dog. He was the friendliest, kindest dog she ever met. Over the years, Oscar had his share of health challenges, including a knee injury and resulting arthritis. His mom gave him all the care he needed, which is why he continued to enjoy a happy, active life.
Oscar starts drinking more water
When it came to Oscar’s eating, drinking, and elimination habits, he was steady as a rock. Which is why it stood out when Oscar’s drinking bowl was empty every time his mom looked. When his mom refilled the bowl, Oscar would drink some more.
Because water intake can fluctuate for various reasons, it wasn’t overly suspicious at first. But Oscar’s increased thirst continued. Oscar’s drinking habits seemed to have changed for good. It was time to see a veterinarian to figure out why.
At the veterinarian
Some health conditions that cause increased thirst can manifest through appearance such as
- jaundice
- pale gums
- abdominal swelling
- and other signs
This is why the veterinarian began by a thorough physical examination. There were no red flags in the way Oscar looked and felt—he appeared perfectly healthy.
The veterinarian went on to analyze Oscar’s blood and urine. The blood test results came back mostly normal. Oscar did not have diabetes, and his kidneys were working well. The one anomaly was Oscar’s liver enzymes.
Oscar’s urine also didn’t show any problems other than being very dilute, clearly reflecting the excessive water intake. But what was behind all that thirst?
The diagnosis
Increased drinking with the elevated liver values made the veterinarian suspect Cushing’s disease. Cushing’s disease is a condition in which the body produces too much cortisol. Like any hormone, there is a useful range of cortisol levels, but trouble ensues when the controls fail.
Further information: The Function of Cortisol: What Happens In A Dog’s Body When It Goes Awry?
Potential symptoms of Cushing’s disease include:
- excessive thirst
- increased urination
- skin and coat changes
- slow-healing wounds
- pot-bellied appearance
- weakness
Oscar had no other symptoms besides the increased drinking. However, he fit general risk criteria. Further, Dachshunds, Terriers, and Boxers have a high risk of developing the disease.
Oscar had to undergo further specialized testing to confirm or rule out the suspicion.
Source story:
Oscar the 14-year-old Terrier
Related articles:
Symptoms To Watch For In Your Dog: Excessive Drinking (Polydipsia)
Further reading:
Why is My Dog Drinking So Much Water?
We must always be vigilant in watching changes in behavior with our pets.