17 y/o doxie with possible Cushings disease

Have they done a urinalysis? If that shows the possibility of infection it's a good plan. If not, probably not the best way to spend your money. I'd worry about the possibility of Lepto if there was a possibility of exposure. Money would be better spent doing a lepto titer, but all this is without every seeing and examining your dog, best to discuss with your vet.

There are so many things that can cause a hepatopathy that working through diagnosis is a step by step procedure, ruling out the most probable while trying to treat the liver problem.