HIGH PREVALENCE OF MYCOBACTERIUM AVIUM SUBSP. HOMINISSUIS IN A BATCH OF QuARANTINED Pigs IN CROATIA

Tuberculosis is a common occurrence in pigs, which are susceptible to infection with both Mycobacterium (M.) avium subsp. avium and M. avium subsp. hominissuis. The aim of this study was to present a case of tuberculosis in a batch of quarantined pigs, imported to Croatia from Austria. Diagnostic examination of 125 quarantined animals included a comparative tuberculin skin test with avian and bovine tuberculin. As 67.2% of pigs showed either positive or suspicious reaction to avian tuberculin, the animals were retested. The results of the second skin test revealed an even higher proportion of reactors (91.1%). Therefore, the State Veterinary Office ordered slaughtering of the animals, and post-mortem examination (gross examination and bacteriology) of the lymph nodes of 121 pigs was performed for diagnostic purposes. Gross tuberculous lesions were observed in 107 pigs (88.59%), mostly in mesenteric lymph nodes (52.1%). M. avium subsp. hominissuis, identified with molecular methods, was isolated from 113 pigs (93.4%). This report stresses the importance of effective preventive and control measures which are necessary on farms raising animals for breeding purposes.