Re: 16 year old dog- kidney problems / arthritis, recent medicine change - bad.
Hi
I would run a SNAP 4 on this dog ASAP this will check for 3 Tick born diseases. Lyme causes kidney problems in many of it's victims. The treatment could be as simple as Doxycycline, but if left for long it is very hard to treat.
My dog had Lyme and Anaplasmosis he suffered from the same things you mentioned. And had the high elevation in the liver levels (Anaplasmosis causes that). His ALT was over 1200, BUN, Creatin were elevated also, you may also see, lymph glands swollen and edema in hind legs, also those lymphs nodes maybe swollen and causing the limping.
The dog may act like they don't see well at night and barks, this is from edema in the eyes (orbital edema).
I am using Samento (cat's Claw) for my dog, it is working wonderfully. He was on Doxy for 5 mos before we could get him off of it with out relapsing.
Join the Tick-List they can help you a lot if the dog comes back positive.
K