Influence of type and breed of horse on serum osteocalcin concentration, and evaluation of the applicability of a bovine radioimmunoassay and a human immunoradiometric assay [corrected]

OBJECTIVES

To evaluate applicability of a human osteocalcin (OC) immunoradiometric assay (IRMA) for use with equine serum and compare it with a bovine radioimmunoassay (RIA) previously proven valid for such samples, and to describe the effect of type and breed of horses on serum OC concentration.

ANIMALS

100 healthy horses of either sex, classified as type I or II (draught or warmblood, respectively). Each type was represented by 2 breed groups, each comprising 25 horses.

PROCEDURE

Blood samples were collected in the morning, and the serum was separated. Osteocalcin was measured, using commercially available RIA and IRMA kits, according to the manufacturer's instructions. All samples were evaluated in duplicate.

RESULTS

The human IRMA did not recognize equine OC. Significant variations in the bovine RIA results were observed between types of horses. Draught horses had lower OC concentration, compared with warmblood horses. Significant difference was not observed between breeds for type of horse. Sex had no influence on serum OC values, but age was a significant covariable for both types of horses.

CONCLUSIONS

No crossreactivity exists between the equine and human amino- and/or carboxy-terminus of OC, using this particular human IRMA kit. Difference in blood OC concentration exists between draught and warmblood types of horses.

CLINICAL RELEVANCE

Use of this human IRMA kit is not valid for equine serum. Horse type must be taken into account when evaluating OC concentration in research or clinical situations, especially if small variations in OC concentration are expected.

[Chronic interstitial nephritis in cattle with cardiomyopathy]

We tried to characterize the chronic interstitial nephritis as it occurs in bovine cardiomyopathy (CMP). For that reason conventional analysis methods were applied to urine of healthy and CMP-diseased cattle. With all the sick animals used for this study a nephritis of the mentioned type was diagnosed pathologically. By discriminant analysis of our data we were able to show, that the chronic interstitial nephritis due to CMP was best described by the variables protein (precipitation by heat), renal epithelial cells and leukocytes. In 73% of all the affected cattle one or more variables were changed pathologically to a minor to moderate degree. In the remaining 27% they were within the normal range. A possible microhematuria was secondary. Using identification analysis all the healthy animals and 69% of the diseased ones were made out correctly. As a consequence of this study we conclude, that further methods are necessary in order to recognize the different forms of nephritis more reliably.

[Cardiac and circulatory physiological studies in cattle with and without cardiomyopathy]

Cardiovascular examinations were performed on 29 Red-Holstein-Simmental cows, suffering from cardiomyopathy. We compared the results with those from 18 healthy animals. The cows with cardiomyopathy showed a higher heart rate, a higher and broader P-wave, a prolongation of the electric systole in relation to the RR-Intervall, an increased systolic and diastolic pressure in the right ventricle and in the pulmonary artery, a higher peak pressure rise in the right ventricle and a lower peak pressure rise in the left ventricle with lower systolic and higher diastolic pressure. A lower oxygen content in the right-ventricular blood and lower carbon dioxide content in the left-ventricular blood of the sick cows may be due to a longer circulation time. The observed pulmonary hypertension is probably the result of the left heart insufficiency and is being discussed with regard of the histopathological alterations in the heart muscle and the pulmonary vessels. Possible reasons for the cardiomyopathy are described and evaluated.

The cells of equine blood and their development

Based on morphologie studies on bone marrow, lymphnode and blood preparations the cells of equine blood and their developmental stages are described and illustrated with 32 coloured photographs.