To contribute to the enzymological diagnosis of equine hepatic disorder, the levels of serum sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), and isocitrate dehydrogenase (ICDH) were determined in 50 healthy racehorses in Japan. When expressed with mean and standard deviation, they were 1.4±0.56 for SDH, 1.5±1.1 for GLDH, and 11.1±3.2 for ICDH(mU/ml, 25°C). Mainly, lactate dehydrogenase(LDH), glutamate oxalacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (A1-P), r-glutamyl transpeptidase (γ-GT), and a-hydroxybutyrate dehydrogenase (α-HBD) were measured for three weeks in three cases of equine liver dysfunction, which had been induced by oral administration with 0.4m1/kg of carbon tetrachloride (CC14). Among these enzymes, the change of γ-GT activity was discussed especially. A concomitant significant increase was observed in serum SDH and GLDH activity after CC14 administration. A maximum peak of SDH activity was observed 24-48 hours later and GLDH activity 3 days later. Serum ICDH activity was not significantly high, as compared with SDH and GLDH. One week later, SDH, GLDH, and ICDH activities returned to their levels determined before CC14 administration. On the other hand, γ-GT maintained considerably high activity for three weeks. From the results of this experiment, it was assumed that SDH and GLDH might be available for the diagnosis of acute liver disease in the very early stage, and γ-GT for the diagnosis of chronic liver disease.
There were three large-sized solitary cysts in the liver of each of two horses, Nos. 1 and 2. Horses 1 and 2 were a 16-year-old halfbred gelding and a 22-year-old female Thoroughbred born in Ireland and England and imported into Japan at the age of 6 and 5, respectively. All the cysts were unilocular and had numerous brood capsules containing protoscolices in the interior. Their wall consisted of an inner germinar layer, an outer cuticular membrane, and calcareous corpuscles. Each cyst was surrounded by the host capsule . All the cysts were morphologically identified as those of Echinococcus unilocularis (larvae of E, granulosus). In horses 1 and 2, the cysts were found to belong to E . polymorphus and E. cysticus, respectively, when classified on the basis of morphology. All the cysts were also diagnosed as those of Es fertilis on the basis of the existence of protoscolices . The following surmise may possibly be made on the hepatic hydatid cysts in the two horses : It is within the bounds of possibility that the cysts may be larvae of E, granulosus equinus and that the infestation of the parasite may have occured to the two horses in Ireland and England, respectively.
A six-year-old saddle horse with cardinal clinical signs, such as edema of the lower part of the limbs, languishment, and occasional diarrhea, was studied pathologically. A diagnosis of equine miliary tuberculosis, which had rarely been reported in Japan, was made in it. There were notably distinct gross changes on the serous membranes of the thoracic and abdominal cavities. The changes consisted of the multiple to scattered occurrence of both miliary nodules 1 to 3 mm in diameter and fibrous villi of varying shape. The multiple occurrence of miliary nodules of the same kind was also seen in the lung. Lymph nodes were swollen almost all over the body, especially the anterior mesenteric lymph node. Histopathological examination revealed that the nodules were composed of obvious productive granulomatous tuberculous lesions (tubercle formation). The fibrous villi sometimes included specific tuberculous lesions. The lymph nodes were affected with pronounced granulomatous tuberculosis. Acid-fast bacilli, supposedly tubercle bacilli, were only occasionally stained out within tuberculous lesions in the lung, liver, and anterior mesenteric lymph nodes. The site of primary infection was obscure in the present case. In terms of the generalization of the tuberculous lesions, it was speculated that dissemination through the body of the causal organism might possibly have occurred by means of lymphogenous spread.