Another thing you might want to try for the thyroid is a product called Thytrophin PMG. It is basically bovine thyroid extract. It is made by the company Standard Process. I have purchased their products in the past from spinelife.com. My last dog had hypothyroidism and was on prescription medication for it for a while. I then read about the Thytrophin and added that while removing the Rx from her supplements. Her thyroid levels were actually balanced better with the Thytrophin.
Have you given him any type of de-wormer? The dog I have now had high liver enzymes for her first couple blood tests after I adopted her. I gave her a couple rounds of the Humaworm for pets over a period of time, and her last bloodwork showed normal levels. A couple of the levels associated with the liver can be signs of parasites and not a bad liver. My dog and I both now take Humaworm three times a year. As a matter of fact, we just started our last round this past Friday.
You may also want to try colostrum for the immune system. Hypo-thyroidism is an auto-immune disorder. If by chance you are still getting your dog vaccinated, stop immediately. They are extremely bad for dogs with auto-immune disorders.