NATURALLY-OCCURRING TYZZERS DISEASE (BACILLUS-PILIFORMIS INFECTION) IN COMMERCIAL RABBITS - A CLINICAL AND PATHOLOGICAL-STUDY

  • 1 January 1985
    • journal article
    • research article
    • Vol. 16  (1) , 69-79
Abstract
Tyzzer''s disease was detected in 9 unrelated, commercial rabbitries. During the acute stage of the disease, recently weaned rabbits showed profuse watery diarrhea. Mortality was 14.2-41.2% during the first 3 wk of the outbreaks. In surviving animals, there was a chronic evolution with depression, anorexia, loss of weight and sometimes extreme cachexia. Reproduction animals were less badly affected. Multifocal hepatic necrosis; focal myocardial necrosis; patches of mucosal necrosis in ileum, cecum and colon; and marked cecal edema were most prominent at autopsy. In histological sections of the liver, bundles of slightly gram-negative and Giemsa-, periodic acid Schiff and Ag-positive rod-shaped bacilli were established in apparently viable hepatocytes bordering foci of necrosis. They were also present in myocytes around necrotic foci in the heart and in enterocytes and smooth muscle cells of the muscularis mucosae of the intestinal mucosa. Transmission EM showed that these organisms had an ultrastructure similar to Bacillus piliformis. Most antibotics used failed to combat the disease. Only oxytetracycline was active.