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.