Most of the time we think and concentrate on the kidneys. The liver can also be a problem. My 14 yr old blk/wht, Nika was going through what the vet thought were back related whimpering and crying episodes with darting around and hiding under the dining room table.
The vet gave me the usual pain meds which by the way are bad for the liver. I went to a holistic vet and she mentioned that her liver enzymes were high from her blood test done at the original vet. The original vet didn't mention it. Her thyroid also showed low T4 that the original vet gave me thyroxine for.
But before I went to the holistic vet my friend Susan who has Apu Basenjis (since 1973) told me right away get her on the liver cleansing diet.
Please see this link.
http://www.canine-epilepsy.com/Liver%20cleansing%20diet.htm
The changes started to occur pretty quickly. I took her off the pain meds after 3 days at the start because it wasn't handling the problem. I didn't think it was a back problem. You can really get some amazing results from that diet. She's been totally quiet, relaxed and drinks a lot less water.:)
It's great diet to even put your B on or any dog for a little while and it will clean their system and liver up. Overweight, poor coat, drinking a lot of water, no energy, dog being irritable are some signs of a liver issue.
It always a good idea to have blood tests done just to make sure all is OK.