I dropped Shiver off at the vet's office for a day of tests. They were supposed to check for Cushings but after doing a blood panel, they decided not to test for that after all. The vet could feel his enlarged liver and his liver levels were off the chart. Everything else seemed to look pretty good. He still has the raging heart murmur; he's doing as well as can be expected with the medication though. The vet thinks the liver problems are related to the heart problems. She suggested I could get an ultrasound to see if there might be another cause.
He came home with two new medications so he's on a total of four now. These meds are very expensive and I'm not sure how much longer I can afford them. I'm just really grateful he's already doing better with the new meds and am determined to find a way to make sure he can continue with them for as long as possible.