Labs show a bun of 2, but total protein plasma is high at 8.4. albumin is 3.8. feeds are formula and past low bun has been lack of protein. ?

Probably ok: Everything has to be taken in context. There are no simple answers. BUN is a waste product of protein metabolism and low level is not necessarily bad . The Albumin level is good and reflects enough protein nutrition. In this case total protein may be high because of high globulins which again may be ok in a 9 yr old. Normal weight and growth is more reliable, + indicative health than lab test.