Introduction

Johne's disease or paratuberculosis is an infectious disease, caused by Mycobacterium paratuberculosis, which has been described in numerous ruminant species. In cattle, intractable diarrhea, emaciation and hypoproteinemia in animals older than 19 months characterize the disease. This study was conducted to detect the presence of paratuberculosis in cattle in Shahrekord region from March to August 2001.

Methods and Materials

In order to investigate the presence of paratuberculosis in Shahrekord region, 400 cattle that were older than 4 years, examined clinically in Shahrekord slaughterhouse. All cattle were inspected after slaughter and samples from 54 cases that showed thickening of different parts of the intestine and enlargement of mesenteric lymph nodes were obtained for histopathologic examination.

Results

At microscopic examination specific histopathological characteristics of paratuberculosis were observed in 9 cases. In 6 cases of them massive infiltration of macrophages and giant cells that contained large numbers of acid-fast organisms and numerous lymphocytes were observed in lamina propria and submucosa of intestine in Ziehl - Neelsen staining. In other cases only macrophages containing acid-fast organism and a little number of lymphocyte were observed. In addition, all cases showed infiltration of macrophages containing bacteria in cortex of mesenteric lymph nodes.

Conclusion

The results of this study showed the presence of paratuberculosis in Shahrekord region and the prevalence of the disease in cattle above 4 years old are 2.25 percent.