Icterus condemnations compose a substantial proportion (41%) of total condemnations of bob veal, the class of veal composed of calves < 3 weeks old and weighing up to 68 kg. At postmortem examination, bob veal condemned because of icterus have generalized yellow discoloration of tissues, which is commonly associated with large, yellow liver (fatty liver), and a paucity of other gross pathologic changes. To establish that the generalized yellow discoloration was attributable to high tissue bilirubin concentrations and to examine the underlying mechanism(s) that might be responsible, blood samples and tissue specimens were obtained from clinically normal and icteric bob veal calves at slaughter. For comparison, blood samples were collected from clinically normal, 1- to 5-day-old Holstein calves being raised on local dairy farms. Hematologic and serum biochemical analyses were obtained for the 3 groups of calves (normal local, normal slaughter, and icteric slaughter), and tissues of slaughter calves were examined for histologic evidence of inflammatory or degenerative changes. Mean +/- SD total bilirubin concentration and creatine kinase (CK) activity in icteric bob veal (3.3 +/- 0.8 mg/dl; 869 +/- 788 U/L), normal bob veal (1.4 +/- 0.7 mg/dl; 486 +/- 890 U/L), and normal local calves (0.5 +/- 0.2 mg/dl; 156 +/- 158 U/L) were significantly different. When data for both normal and icteric bob veal calf groups were combined for analysis, total bilirubin concentration regressed significantly on hepatic lipid scores (P = 0.00003) and CK activity (P = 0.00049). Colostrum consumption was determined by measuring serum total protein concentration and serum gamma-glutamyltransferase activity. Bob veal calves that had not consumed colostrum had significantly higher total bilirubin (P = 0.00005) and CK (P = 0.0008) values. It was concluded that normal and icteric bob veal calves have significant increase in total bilirubin concentration, and icterus of bob veal calves is secondary to unconjugated hyperbilirubinemia. Lack of colostrum consumption was strongly correlated with icterus in bob veal calves.

Activities of diagnostically important enzymes were measured in serum and lysates of liver, kidney, skeletal muscle, heart, intestine, lung, and pancreatic tissues from wild-caught yellow rat snakes, Elaphe obsoleta quadrivitatta. All samples were analyzed for alkaline phosphatase, lactate dehydrogenase (LD), aspartate transaminase (AST), alanine transaminase, gamma-glutamyltransferase, and creatine kinase (CK) activities. The major enzyme activities found in the liver were LD and AST. The kidney had moderate activities of LD, AST, alanine transaminase, and CK. Skeletal muscle and heart contained high CK activity. Intestine, lung, and pancreas had low activities for most enzymes analyzed. Little to no gamma-glutamyltransferase activity was found in serum or tissues analyzed. Serum enzyme activities in yellow rat snakes were similar to those described for other reptile species, except for serum CK activity, which was increased in rat snakes.

The concentration of carbonic anhydrase III isoenzyme (cA-III) in serum samples from 216 clinically normal Thoroughbreds was determined by use of an enzyme immunoassay. The concentration range of cA-III was from 16.0 to 254.5 ng/ml (mean, 56.5 +/- 11.9 ng/ml). Significant differences were not detected according to age or sex. To confirm whether serum cA-III concentration was high in horses with muscle disease, serum samples of 11 horses with exertional rhabdomyolysis were analyzed by enzyme immunoassay. Their serum cA-III concentration was about 56 times (3,136 +/- 2,610 ng/ml) that of healthy Thoroughbreds. Concentration of cA-III was higher in horses with rhabdomyolysis that had been transiently recumbent than in horses with mild disease that were reluctant to move. Blood samples obtained serially from 6 horses with exertional rhabdomyolysis were studied. Serum activities of aldolase, creatine kinase, aspartate transaminase, and lactate dehydrogenase were high. Increases and decreases in concentration of cA-III were more rapid than that for aldolase, creatine kinase, aspartate transaminase, and lactate dehydrogenase activities; thus, cA-III may be clinically applicable as a diagnostic marker for muscle disease in horses.