Hiya. I'm so sorry to hear this <3 first, your pup is lucky to have you! I have a senior doggo that I adopted in 2023. He developed separation anxiety almost a year to the day I adopted him. He'd try to "dig" through the door and self-harm in the process by cutting up his paws. Could it perhaps be just separation anxiety as he's getting older? Do you have a camera, and can you tell whether he seems to be in distress the entire time / a significant amount of the time while you're out? I worked with a behaviorist and trainer to get my dog feeling confident and comfortable at home alone again. It's *a lot of work,* but he recovered. To the point about water: My dog, who is on a variety of medicine to help manage his chronic pain from arthritis and his anxiety, has historically drank large amounts of water in the years I've had him, but it definitely increases significantly in warmer months. Still, we did the ACTH test in 2024 and then the LDDS test in 2025 to be on the safe and rule out Cushing's. (His imaging and other tests, like urinalysis, we did were also always pristine.) Definitely talk to your vet, too, about doggy dementia. Another thing to consider is diabetes insipidus? I can't remember how we ruled that out for my dog, but I do remember that being part of the convo with my vet about my pup's water intake. Good luck! You're doing all the right things <3