Inclusion body disease (IBD) affecting boas and pythons is a serious and common disease. Boas can be clinically healthy carriers, which makes control of the disease difficult. The causative agent has not yet been confidently identified, and therefore there are no serodiagnostic tests available. Today, histopathologic examination of tissue biopsies is the recommended antemortem diagnostic method, but there are several disadvantages. The objective of this study was to compare the sensitivity of two diagnostic methods ? liver biopsies and blood smears, and to evaluate ultrasoundguided needle biopsy of the liver.