Hi again, Laurie. First off, I want to address your earlier question about the timing of Davis' monitoring ACTH testing (3-4 hours after dosing). For quite some time now, Davis has advocated for a testing window that is a bit earlier than Dechra's. I can only speculate that perhaps Davis thinks it is more likely that they are catching the cortisol at its absolutely lowest point by testing within that window. Regardless, as long as all of Charlotte's monitoring tests take place within the same time frame, I don't think that should present any problems because you will be comparing apples-to-apples, if you will.
As far as the tremoring, since it started even before the trilostane treatment, it does seem as though something other than low cortisol is likely involved. Coupled with Charlotte's lethargy and lack of appetite, one disconcerting possibility is that the pituitary tumor that is causing the Cushing's may be enlarging and putting pressure on other areas of her brain. Given the shape of a boxer's skull, I believe that she may be at a heightened risk for this problem, and that may be one of the possibilities that is prompting the Davis internist to suggest a neurological consultation. Unfortunately, neurological diagnostics and subsequent treatment can be quite expensive. I know this personally because my husband and I opted out of pursuing neurological imaging or treatment for our own Cushpup, partly due to the expense. We ultimately ended up losing him to what we assume were the effects of an expanding tumor.
Under your current circumstances, I believe I would just try to hold tight until the ACTH is performed, and if at all possible, it would be great if your vet could also run at least a very basic blood chemistry panel. Those tests alone may provide you with some answers, especially if it appears as though a dosage change is warranted. However, if Charlotte's cortisol level is optimal at the same time that the tremoring and other problems worsen, then some other decisions may need to be made. I don't want to worry you unnecessarily about an enlarging pituitary tumor, but I do feel compelled to mention it because I do think it is a possibility.
I surely understand your frustration and sorrow over these medical costs. In a perfect world, we'd hope to be able to opt for any treatment or any test that's necessary. But very few people are lucky enough to be able to do that, and the rest of us have to choose whatever will deliver the best hope for the least cost. I do think the money spent on the next ACTH will be worth it. And then, as I say, you may have a better idea as to whether there is value in looking elsewhere for the source of these problems.
Please hang in there, Laurie. You've done a great job of advocating for Charlotte, and she's very lucky to have you as her mom.
Marianne