elevated enzyme levels

[Beverly540@aol.com]

Hi everyone,
          My mare, Flower, tied up twice, was treated, and we were all hoping
that everything was back to normal. Our vet wanted to do a follow up test of
her enzyme levels, which we did. The news regarding her enzyme levels is
perplexing and we are wondering if anyone else has any experience with this
scenario.
History
Tie-up  8/29
Tie up  9/13      
Enzyme test  9/21
Repeat test   10/21
I am not a vet or chemist so please excuse my fumbling attempts to
explain......
Our vet said that the muscle enzymes have a half-life of 24 to 48 hours and so
her enzyme level tests should not have been as elevated as they were given the
amount of time that elapsed between the tie-up and the two tests. She said
Flower's muscle emzyme *CPK* and *GGT*  levels were both elevated.
Furthermore, the level did not change much during the four weeks between
tests. Flower's thyroid level is normal. 
             Our vet is baffled. She recommended that I collect a urine sample
for  a "fractional excretion" test.  She also recommended that I post to
ridecamp to see if any of you have experience with this problem.  
              My husband thinks I over-electrolited her. I doubt it......I
think she's getting too much salt  and minerals..........he doubts it. Vet
says it's not her sodium that's high, anyway. Hubby's in charge of salt and
minerals, I'm in charge of electrolites. Help, anyone?????
Thank you and happy trails,
Beverly and Flower
Blue Ridge Mts. of SWVA