The Use of LDH Isoenzymes to Differentiate Three Medical Conditions in Cetaceans
Thomas H. Reidarson; Jim McBain
Higher than normal levels of lactate dehydrogenase (LDH) are released
into the blood of humans during a number of medical disorders including hepatopathies and
myopathies. A key to differentiating these conditions lies in the LDH isoenzyme profile.
Since cetacean diseases involving liver and muscle also produce rises in LDH, we compared
the LDH isoenzyme profiles which followed the use of triazole antimycotic drugs and those
associated with apparent hepatopathy and uterine disease.
The triazole drugs, Itraconazole and ketoconazole, produced equivalent
relative rises in all five LDH isoenzymes. All isoenzymes returned to normal 4 to 6 weeks
following discontinuation of therapy. Three bottlenose dolphins with suspected hepatopathy
developed significant rises in LDH, HBD, AST, ALT, and bile acids; the LDH isoenzyme profile
appeared quite different from that observed with the triazole drugs. In these cases there
was a significant relative decline in LD1 and a rise in LD4. Uterine pathology resulting
from dystocia in a beluga whale and spontaneous abortion in a killer whale resulted in a
rise in serum LDH levels above normal with a significant relative decline in LD1 and LD2,
and a rise in LD4 and LD6.