Do you have the ranges for the ACTH? I think 18 is the usual cutoff or upper limit for a normal reading but am not sure. Either way that post of 18.4 is not enough to definitively diagnose Cushing's especially in a diabetic dog. The LDDS should not be used in diabetic dogs however so that leaves you with only the ACTH for diagnosing Cushing's in Eli. Diabetes can and does cause false positives on the Cushing's tests especially if the glucose is not controlled. On the flip side it is very difficult to control the glucose if Cushing's is present.

But a diabetic dog should not even be tested for Cushing's until every option for controlling the glucose has been exhausted and the dog is becoming intolerant to insulin. This doesn't happen quickly but over a long period of time to my understanding. So if Eli is new to diabetes I would be even less sure of him having Cushing's. I encourage you to join our sister group, K9Diabetes, found here:
http://www.k9diabetes.com/forum/
Sadly as is the fate of many online forums, they are not as active as they once were. However you can find much valuable information there. If you are on Facebook, please join this group for canine Diabetes -
https://www.facebook.com/groups/Cani...ndInformation/
The adrenals being enlarged on the ultrasound is something we do see in dogs with Cushing's however. But again with the low ACTH result I am still not convinced Cushing's is present. It IS possible that Eli is in the very early stages and if that is the case then you will start to see things like a ravenous appetite, excess peeing and drinking, panting for no reason, seeking cool places to lay, hair loss or failure of the hair to regrow after a cut or shave, and a pot belly.
The dose of 30mg of Vetoryl was too high for him even if he does have Cushing's. The starting dose should have been closer to 20mg per day based on his weight of 21 lbs. I would have been happier with 10-15mg per day to start.
The amylase could be indicative of a problem with the pancreas but without the normal ranges I'm not sure how high that actually is. Vomiting, diarrhea, and lethargy ARE definitely signs of pancreatitis tho so that is something I would be asking the vet about asap. There is a test called the cPL or cPLI that is specific for this condition and I would be talking to the vet about this if Eli starts having the same problems now that the Vetoryl has been stopped. If he continues to improve, then the odds are what you saw was due to the drug.
As for the supplements and herbs you are using, I don't see any problems with them. Keep in mind these things don't work as fast as pharmaceutical drugs so you won't see any lab changed for several months. The ALP won't be affected at all by these things but it is not one of the liver enzymes that need concern you overly much. The ALT, AST, and GGT are the enzymes that tell us something is happening to the liver; the ALP just tells us that the liver is working hard at the moment. I would talk to the people in the diabetes groups tho to be sure these things are alright with a diabetic dog.
I am very glad he is doing better and hope that trend continues!
Hugs,
Leslie