Johne's disease in dromedary camel: gross findings, histopathology and PCR

Abstract

This study was conducted on dromedary camels suffering from disease suspected Johne's disease. The clinical signs were chronic watery diarrhoea, emaciation and decreased milk production. Intermandibular oedema was noticed in 2 cases. Several investigations were performed, staining of intestinal smears with Ziehl–Neelsen stain, histopathology and PCR. Gross pathological examination revealed thickening of the intestinal wall with corrugation of mucosa which extend in some cases to the colon and rectum along with granulomatous reaction in liver. Mesenteric and ileocaecal lymph nodes were moderately large and oedematous. Histopathological lesions were diffuse granulomas characterised by extensive macrophages and epithelioid cells infiltration into the mucosa and submucosa of small intestine and colon, with numerous acid-fast organisms. The ileocaecal lymph node as well as, the other mesenteric lymph nodes showed sinus histiocytosis, infiltration of macrophages and epithelioid cells containing acid-fast bacilli. The different tissue organs and faecal sample of infected camels with Mycobacterium avium subspecies paratuberculosis were strongly positive by IS900 PCR.