Kathy, I applaud your effort to provide information to our members about macroadenomas! Like you, I suspect that they may actually be more common than was previously thought. I know you have been interested in hearing more about my own Cushpup, Barkis, who we assume had developed a macrotumor at the time that we lost him. However, his pituitary gland was never imaged so I cannot tell you with certainty that an enlarging tumor was the cause of his problems. However, I am very willing to share our experience, regardless.

Barkis was diagnosed with Cushing's eight years ago at the age of nine. Like many dogs, he had slowly exhibited an increasing set of symptoms over time that finally "came together" in support of a classic profile: hair loss on his haunches and sides, panting, increased thirst/urination, ravenous appetite, hindleg muscle wasting, low T-4 and elevated liver enzymes. In conjunction with the symptom profile, he was diagnosed on the basis of a "positive" ACTH and bilaterally enlarged adrenal glands on ultrasound.

At the time of diagnosis, trilostane was just being introduced in the U.S. I had already heard about it through the original EZBoard Cushing's forum that preceded k9cushings.com. My IMS had attended international conferences in which it was being discussed, and he was interested in trying it. I jumped on board and we agreed that Barkis would be his first trilostane patient. At that time, there was still a lot of uncertainty and variation in dosing protocols. Barkis started out and also ended up on a much higher dose of trilostane than would be currently advised. But for approx. six months, he generally did well on the trilostane and we saw a great deal of improvement. In fact, we saw improvement in his thirst and hunger within just a couple of days of starting treatment. However, even on the high doses of trilostane, his post-ACTH results were never lower than around 6.0 ug/dl or so.

I say that "generally" he did well. There was one significant exception. Even prior to beginning the trilostane, I noticed some odd tremoring episodes. Sometimes when I held him, it seemed as though he was shivering across his shoulders. It wasn't constant, just once in a great while. Within a couple of weeks after starting the trilostane, the tremoring episodes became much more frequent and much more pronounced. They happened most often when he was at rest -- laying down or even asleep. They didn't seem to bother him at all, but they totally freaked me out. A basic neurological exam didn't reveal any explanation, and we didn't get the chance to videotape them before they stopped just about as abruptly as they had begun. To this day, I do not know what caused them or whether or not they were related to his pituitary tumor.

Everything proceeded well for a few more months. But I started noticing some subtle changes and some not-so-subtle changes. He just seemed a bit "off" and not as perky. More importantly, he started to lose his appetite. Unfortunately, these changes occured while he and I were out-of-state, away from home and staying with my mom in the aftermath of her having suffered a major heart attack. So I was very stressed and my attention was divided between the two of them. During the month that I was away from home, we stopped Barkis' trilostane and then restarted it at a lower dosage. He seemed a bit better, but I still knew that something was wrong. By the time we returned home, I knew something was VERY wrong. His ACTH was fine, however, as was all his other labwork. So my IMS suggested that an enlarging tumor might be the source of the problems, and that a CT or MRI would be required in order to know for certain. If we were to go that route, we wanted to take him to the Auburn vet school because they had a fine reputation re: radiation therapy. But that meant driving him to Alabama. While we were debating the imaging, Barkis went into a swift decline:

Acted distant and dazed, as though "he" was leaving us;
Was very restless;
Started pacing endlessly through the house;
Started relieving himself in the house and in the car;
Lost his balance and coordination.

The crisis came suddenly when he stopped eating and drinking entirely. We had stopped the trilostane by that time, and again his cortisol level/labwork was fine. The hardest part was that he acted thirsty and would walk over to his bowl and lower his head and try to lap up water. But his tongue just wouldn't make contact with the bowl -- it was as though he had lost the ability to understand how to coordinate his mouth. It was awful, and that was when we said, no more. Our IMS thought it still might be possible to buy him some quality time with radiation therapy. But for a variety of reasons, we decided against it. At that time, the only option was a month-long course of twelve treatments all requiring general anesthesia. We instead made the decision to release him from his tired, sick body.

Without the imaging, I will always be left with questions. And that part is hard. Even though all his symptoms pointed in that direction, we do not know for certain that his tumor was enlarging. However, since we decided we were not going to opt for radiation therapy regardless, at the time there seemed little point in subjecting him to imaging precedures at a great expense on so many levels.

And even now, I cannot say that I, personally, would go so far as to recommend initial CT or MRI screening for all dogs who are diagnosed with pituitary Cushing's. For an owner who would have the means and ability to pursue treatment for a macroadenoma (either radiation or surgery), then a screening image could be very helpful. But for many folks, finding the money for the basic diagnostic tests and medication is such a stretch in and of itself. And if the pet parent feels as though they would not be able to pursue treatment in the event that a macrotumor is identified, then the imaging may not be serving a useful purpose unless the dog develops symptoms that make a macrotumor seem likely and the owners decide they want confirmation of the problem. But that is just my personal opinion, and of course I am influenced by the decisions that we made about Barkis.

Kathy, I see that I have written a book here -- probably more than you ever wanted to know! But I do want to tell you that my heart resonates with you over your loss of Macy. And I think you are doing her a grand honor by wanting to help other dogs and parents who may be facing a macrotumor. In this way, you are continuing to celebrate her spirit and her bravery ~ today and everyday.

Marianne