HISTOLOGICAL EVALUATION OF THE GUT OF NILI-RAVI BUFFALOES FOR DIAGNOSING PARATUBERCULOSIS

Bubaline paratuberculosis is a chronic, debilitating disease that has been implicated in causing reduced milk yield and poor carcass quality in affected animals. The objective of the current study was to depict the histopathological manifestations of paratuberculosis in subclinically infected Nili-Ravi buffaloes. For this purpose a total of 53 slaughtered carcasses were selected on the basis of thickened/ corrugated intestinal mucosae along with edema of the associated lymph nodes. Acid-fast bacilli (AFB) were observed only in 22.64% of the cases on smear method examination. Histological examination of the tissue samples was performed using hematoxylineosin and Ziehl-Neelsen staining methods. Heavy mononuclear cells infi ltration was detected in the tissues. The foamy cytoplasm of epithelioidmacrophages was observed to be engorged with AFB in the positive cases. The results of this study demonstrated tissue sections showed much higher positive results (100%) as compared to the smear method (18.68%). Furthermore, the overall histological representation of tissue sections was more defi ned and illustrative than their smears. The histologically positive cases were also confi rmed by means of ELISA testing. Despite being a timehonored technique, histopathology is an incredibly accurate and reliable protocol for diagnosing bubaline paratuberculosis.