Re: Diagnosis
Hi Amy and welcome to you and Frankie!
These are my thoughts which others may not agree with but that is the good thing about forums like ours - you are presented with information from more than one source that may make a light bulb come on for you. 
I have some concerns about the diagnosis. Cortisol will rise naturally in response to any stress, internal or external. My first pup was diagnosed based on the LDDS, HDDS, ACTH, and UTK panel but the ultrasound found a tumor on her spleen. Once that was removed all her tests returned to normal. She did eventually develop conventional Cushing's but at the time of those tests she did not have the disease - it was the tumor that caused false positives on all the testing.
You say her ultrasound was normal except for the liver. In a cush pup we typically see changes with the adrenal glands. With PDH they will both be enlarged. So normal appearing adrenals aren't the norm with Cushing's. A cush pup almost always has high elevations in the ALP with mild elevations in the other liver values. Frankie's ALP is normal - again not the norm at all. In addition, the mast cell tumor could have skewed the LDDS just as the tumor on Squirt's spleen skewed all her tests.
Some of her signs are consistent with Cushing's however...but one thing that makes getting a sound Cushing's diagnosis so hard is that so many other conditions share the same signs and they can skew the tests for Cushing's. With her main issues being excess drinking and peeing in addition to the very dilute urine I am wondering about Diabetes insipidus. This is a rare form of diabetes that has nothing to do with blood sugar but rather with how the body processes water. None of the usual tests can pick this disease up and the test for it, a water deprivation test, is rather risky so if this is suspected the vet simply starts treatment (a nasal spray). If the treatment helps then there is the diagnosis.
I am also wondering why she is being treated for kidney disease if the SDMA was normal? Was the CREA elevated? Even then with a normal SDMA that pretty much rules out kidney disease. So why the renal diet and Benazepril? Low protein for renal disease is no longer recommended until the final stages...it is the phosphorus that needs to be watched instead. So if she is on a low protein diet as a renal diet that may well be causing the hunger as you suspect. With the normal SDMA I would stop that diet and the Benazepril (unless she also has heart issues?). I would get her on a high quality food with moderate proteins and fats.
As for the increasing values on the ACTH....are you giving the Vetory with a meal every time? And is the ACTH being performed 2-4 hours after the pill and meal? The vet isn't telling you to fast for the ACTH are they? If the drug is given with a meal and the test is done during the correct time frame following then in my mind the increasing cortisol could be 1) the dose is not yet correct and an increase is needed or 2) something else is going on that has not been discovered yet which takes me back to my concerns about the initial diagnosis of Cushing's. I would want the ultrasound and additional investigation in your shoes....but that desire is informed by my own experiences with misdiagnoses.
I am glad you found us and look forward to learning more as time passes. Keep talking and asking questions! That's the best way to learn.
Hugs,
Leslie
"May you know that absence is full of tender presence and that nothing is ever lost or forgotten." John O'Donahue, "Eternal Echoes"
Death is not a changing of worlds as most imagine, as much as the walls of this world infinitely expanding.
Reply With Quote
