Cushing's in dogs: what I actually tell owners in the exam room

Let me guess. Your dog has turned into a bottomless water bowl, wants out at 2 a.m. like it's a standing appointment, and is suddenly convinced every crumb on the kitchen floor has his name on it. Maybe there's some panting, and he's a little more couch potato than usual. And now your vet has said the word "Cushing's."

Take a breath. Let's walk through it the way I would if you were sitting across from me.

The lab value I see high every single week

The most common clue is a liver value on bloodwork called alk phos (ALP). I see it high several times a week. Here's the thing: a high alk phos does not automatically mean Cushing's. It just means Cushing's goes on my list of possibilities. Plenty of other things can raise it.

This isn't an emergency

Cushing's is a slow, long-term disease. It doesn't take a dog out overnight. And some dogs don't need treatment at all. If there are no real symptoms, we might just watch. It depends on the dog, the situation, and honestly what's going on in your household.

How I work it up

Once the bloodwork shows a high alk phos, and maybe some of those symptoms, I usually start with an ultrasound. Not every vet does it in that order, but I like it because it does two jobs at once.

First, it checks the whole belly, especially the liver. That's the value that was high, so if this turns out not to be Cushing's, I want to know what else is going on.

Second, it looks at the adrenal glands. These are the two small glands that make cortisol.

• Both adrenals enlarged points strongly to the pituitary form. That's about 85% of cases: a tiny growth on the pituitary gland at the base of the brain. I know "a growth near the brain" sounds terrifying. It isn't a brain tumor in the scary sense, and usually all it does is cause Cushing's. It sends out a hormone that makes both adrenals overwork and get bigger.
• One adrenal enlarged points to the other 15% or so: a tumor in the adrenal gland itself. This is the one I take more seriously. It's typically the more aggressive form, and it usually means surgery to remove the gland, so expect your vet to talk with you about a referral to a surgeon.

So the ultrasound narrows things down. Is it Cushing's, and if so, which kind?

Then the confirming test

The ultrasound isn't the final answer. Next comes a blood test to confirm it. I use the ACTH stimulation test. Some vets use the low-dose dexamethasone test instead, and either one is fine. I prefer the ACTH stim mostly because it's the same test I'll use later to see how your dog is responding to the medication. Every vet's a little different, and there's no wrong way here.

Treatment

Once it's confirmed, the main medication is trilostane, which you'll often see as Vetoryl. It turns down how much cortisol the adrenal glands make, and it's the treatment for the pituitary form. It's given once or twice a day depending on your vet's approach, and either way is fine. Expect the amount to be adjusted along the way. That's normal, not a sign that something's wrong. The adrenal form is different: surgery is usually the answer there, and medication is mostly for dogs who can't have surgery.

What it does mean is rechecks. You'll be back for blood tests, more often at the start, so your vet can see how your dog is responding and fine-tune things. Between the daily doses and the recheck dates, there's a lot to keep straight. Honestly, that's why I built WagNote (full disclosure: it's my app). I kept seeing owners struggle to keep track of everything with conditions like this, so I put it all in one place.

The two things to watch at home

When your vet checks how the medication is working, the bloodwork matters, but so does what you see at home. The two big ones:

1. Water and peeing. Is the drinking coming down? Fewer trips outside, fewer accidents? The best way to know is to measure. Fill a big jug in the morning, fill the bowl only from that jug for 24 hours, and see how much is gone. Write it down with the date, or log it in WagNote and you'll see the trend line over the weeks. "She's drinking about half what she was" beats "I think she's drinking less" every time.
2. Appetite. Is your dog still acting like he hasn't eaten since the Clinton administration, or is he a little less frantic about food? A calmer appetite is a good sign. (Not eating at all is different. That's a call to your vet.)

The one that surprises people: a little stiffness

Here's something I've noticed, especially in older dogs. After they start the medication, some of them seem a bit sore. Stiffer getting up, a little slower on walks.

That's because all that extra cortisol is a steroid, and steroids calm inflammation, including in the joints. So the Cushing's may have been quietly covering up some arthritis. Once the medication brings the cortisol down, the arthritis shows itself.

It's not the medication hurting your dog. If you see it, tell your vet. They may want to start something for the arthritis now that it's out in the open.

If you do one thing this week: measure the water for one full day and write the number down, or log it in WagNote. Your vet will love you for it.