Inclusion Body Disease hos boa- och pytonorm : diagnostiska metoder

Abstract: 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. Sixteen clinically healthy boas aging from 1,5 months to 4 years or more, and from different collections in Sweden were used in the study. Blood samples for blood smears were collected from all snakes, liver biopsies by celiotomy were performed on fourteen, and ultrasoundguided needle biopsies on five. The blood smears were stained with May-Grünewald-Giemsa, and the tissue samples were after preparation stained with hematoxylin and eosin. They were then examined with light microscopy for intracytoplasmic eosinophilic inclusion bodies in hepatocytes or blood cells. Typical IBD-inclusions were found in liver biopsies from four of the snakes, but no inclusions were found in blood smears from the same animals. Sampling by ultrasoundguided needle biopsy resulted in representative samples. In conclusion, a blood smear is not a reliable diagnostic alternative to identify IBD-positive snakes compared to liver biopsies, as liver biopsy by celiotomy or needle biopsy is a more sensitive method. Ultrasound guided needle biopsy is a less invasive technique, but has less control of procedure complications.