DISCLAIMER: I'm not a vet and I have no veterinary or medical background whatsoever. This information on Cushings disease in dogs is not meant as a substitute or replacement for veterinary advice. It's meant for educational and informational purposes only, as a starting point for discussing the diagnosis and treatment of canine Cushings disease with a qualified vet.
My dog is one of those rare, confusing cases. After all the testing was done, the vet said that some of the tests suggested he had pituitary-dependent Cushings, while others suggested he had adrenal-based Cushings. It was a possibility that he had both. We had decided to treat him for the pituitary version since the diagnostics leaned more towards that.
The drug we decided on is called Lysodren (mitotane). The reason the vet chose it was because it's the drug most often used to treat Cushings disease in dogs, and has a great success rate. It's also an older drug with a lot of history. In other words, the veterinary community knows a lot about how dogs tend to react on this drug.
To get started with Lysodren, dogs have to go through a "loading phase" where they take the drug every day until there's a change in one of their symptoms. Every dog is different; for mine, we used the speed at which he ate to be the symptom we were watching. My vet was very careful in explaining that the drug is extremely strong and needs the utmost care in monitoring. If we missed the signs that something had changed, a dog can become Addisonian instead of Cushingoid (a whole different problem). At the first sign of change we were to do an ACTH stim test to see if the medication was working.
Anyhow, things went very well. My dog reacted wonderfully to the drug, his symptoms disappeared, his ACTH stim tests showed the drug was doing its job, and we went smoothly into the maintenance phase of the therapy. During the maintenance phase, I only had to give my dog the drug twice a week to control his Cushings.
Unfortunately, it was only about a month into maintenance that I noticed additional changes in my dog -- and to cut a long story short, he was diagnosed with liver disease. We immediately stopped giving the Lysodren (it's not to be given to sick animals).
I have always wondered if the Lysodren caused the liver damage in my dog. My vet had never seen it happen before, and they treat a continuous stream of Cushings dogs. My dog's bloodwork was clean prior to starting treatment, but it is possible that there was pre-existing liver issues and the Lysodren made them worse. We will never know.
After our experience with Lysodren, I was wary about trying any other drug. It took us 3 months to get our dog feeling better after his liver disease diagnosis, and 5 months for his lab values to get back to near-normal. At that point we started thinking about Cushings again. The vet suggested Anipyrl (selegiline). Anipyrl is supposed to be extremely safe. The issue is that it has a poor history of success with Cushings dogs (it's sometimes used to treat 'doggy dementia'). Apparently it only works with pituitary-dependent Cushings, and only if the tumor is located in a very specific place. Some research suggests that it only works in 20% of Cushingoid dogs; our vet said that in her experience, it only worked in 5%.
Still, we figured we would try since it's a much more benign drug. Three months later there was no change. My dog no longer takes Anipyrl.
I have heard about Trilostane and Ketoconazole, and know very little about them. Lots of people have use them to treat their dogs - you can find many on the K9 Cushings Forum.
Dogs with adrenal-based cushings may be candidates for surgical removal of the nodule or the entire gland itself. This is supposed to be a difficult and risky surgery, best done by an experienced vet. Read more here: Adrenal Treatment
Cushex Drops aren't a medication. It's some sort of supplement that is supposed to help alleviate the symptoms of Cushings Disease in dogs. I want to emphasize that it doesn't treat the underlying cause (the overproduction of cortisol), but is supposed to help dogs feel better. It hasn't been scientifically tested and there's no hard data to back it up... but some people claim it's really helped their dogs.
We tried it. Read: Cushex Drops Reviews.
Many pet owners choose not to pursue treatment. After pursuing treatment for our dog, we can see why! Be prepared - it is an expensive disease to treat. The good news is, the most expensive part of treatment is the beginning, when a number of tests are needed to confirm the diagnosis of canine Cushings Disease; determine what drug to use; and, if required, repeat a number of ACTH stim tests to make sure that the drugs are doing what they're supposed to be doing (and to be sure that your dog isn't being overdosed).
Here's a breakdown of all the diagnostic tests, loading phase, and maintenance costs. I left out the actual costs themselves because it varies widely depending on where you live. My dog was going to start the drug called Lysodren (mitotane) - that's what the "loading phase" below refers to.
To give you a very general idea of costs... by the time we'd run through all the diagnostic testing, the loading phase, and only one month of maintenance therapy... we'd spent thousands of dollars.
We later tried Anipyrl. Although the drug itself is very expensive, no testing is required. It is through the owner's observations that determine whether the drug is working (in our case, it had no effect at all).
Your vet can help you estimate the costs of treatment. If you also have pet insurance, check with them to see if they can cover any of the testing of the medications.
I should also mention that sometimes dogs are deliberately not treated for Cushings. It seems that the excess cortisol can help mask the pain of conditions like arthritis. Once treated for Cushings, the cortisol levels come down and the pain from arthritis (or another condition) can appear. So sometimes it's kinder not to treat.
We personally didn't have the best experience with Cushings treatment -- one treatment (Lysodren) was cut short due to liver disease, making me wonder if it was also the cause -- and the other treatment didn't work at all. That is only our experience. We know several people who had successfully managed their Cushings dogs, plus many more we've 'met' online who are doing the same.
Treatment for Cushings disease in dogs is meant to control cortisol levels and prevent additional health issues arising from Cushings. It can also alleviate or eliminate the symptoms that could be making your dog uncomfortable (excess panting, drinking, urinating, etc). Ultimately, it's all about quality of life.
More on Cushings Dogs: