Health & Medical

My old Lab drank the bowl dry one summer, and I thought it was just the heat. Then he drank the refill. Then he woke me at 3am to go out, every night, and the water bowl needed filling twice a day where once a week had been enough. I told myself he was getting old. Old dogs drink more. That is what I told myself until his coat started coming out in handfuls.

Cushing's disease is what vets call hyperadrenocorticism, a mouthful for a simple problem with a cruel spread. The adrenal glands, two small caps on the kidneys, make too much cortisol. Cortisol is the stress hormone, useful in bursts and wrecking in excess. Too much of it leaches through the whole body and slowly unmakes a dog from the inside out.

What Cushing's actually is

The signs creep. That is the trap. He got hungry — ravenous, the kind where he'd eat a dropped sock and look for more. His belly swelled into a soft round pot, the wasted muscle underneath making the roundness worse. His skin went thin and bruised if he bumped a table leg, and the fur on his flanks thinned to almost nothing. He panted at rest and slept more than he moved.

Two forms exist. About eighty-five percent come from a tiny benign tumor on the pituitary gland at the base of the brain, which nags the adrenals to overproduce. The rest come from a tumor on an adrenal gland itself. Both pour out cortisol. The pituitary kind is treated differently from the adrenal kind, so sorting out which one matters.

The first vet visit, a year before the diagnosis, his urine tested dilute and they treated a suspected infection. It cleared, but the drinking didn't. That is the classic miss — Cushing's mimics a dozen boring problems, and a single test rarely catches it.

The test that splits pituitary from adrenal is the endogenous ACTH test — a blood draw that measures the brain's signal to the adrenals. High signal points to the pituitary, low to the adrenal tumor. Our boy had high signal, the common route. An ultrasound of the abdomen ruled out a visible adrenal mass, which confirmed it without surgery. Knowing the type mattered because the adrenal-tumor dogs sometimes go to the OR, while his kind is managed with a pill.

The long road to diagnosis

Diagnosis was the slowest part. Our vet ran a full blood panel first. The changes there — a high ALP liver enzyme, dilute urine, sometimes a high cholesterol — raise the flag but don't prove it. The real tests are the ACTH stimulation test, where they measure cortisol before and after a hormone injection, and the low-dose dexamethasone suppression test, where a small steroid should shut cortisol down and in a Cushing's dog it doesn't. My guy failed both, cleanly.

Left alone, all that cortisol softens more than the skin. It pushes blood sugar toward diabetes, raises blood pressure, thins the bones, and invites pancreatitis and dangerous clots. Dogs with untreated Cushing's tend to die of the things it enables, not the disease itself.

Treatment depends on the type and the dog. The common drug is trilostane, a daily capsule that tells the adrenals to ease off. It needs regular blood checks to dose right — too much and the dog crashes into the opposite problem, Addison's. Some dogs do well on mitotane, an older drug that chemically trims the adrenal tissue but is less forgiving. Adrenal-tumor dogs sometimes go to surgery if healthy enough to survive it, and removing the tumor can be curative.

This is a management disease, not a cure. We gave the capsule with breakfast, watched his water intake drop within weeks, and got a softer, slower dog back instead of a frantic, bald, thirsty one. Within a month his water dropped from four refills a day to one, and the night pacing stopped. His coat never fully returned and his belly stayed a little round, but he slept through the night and stopped drinking the house dry.

The clue that finally cracked it was the symmetry of the hair loss — both flanks thinning at once, not a hotspot or a scratch. My vet called it bilaterally symmetric alopecia and said it was the most telltale sign short of the lab work.

The cost caught me less than the timeline. Diagnostics ran a few hundred dollars. The monthly medication was modest. The lifelong monitoring — blood work every few months to keep the dose honest — added up over the three years he had left. Worth every cent to see him comfortable.

This is not a substitute for veterinary care. If your older dog is suddenly drinking, peeing, and eating like the world is ending, ask for the Cushing's tests by name. The disease hides in plain sight because its signs look like ordinary aging.