Blood work came back today showing kidney disease.  Not clear how bad until we can get a clean catch of urine.  We mag not get that before we have to put him down due to slow starvation from severe inappetence.  I bought two different bags pf complete feed for him.  He was initially interested in both, but appears to lose interest in eating them shortly thereafter.  I am going back to the barn later tonight to see if he has eaten enough to sustain life.