How clean is a mini-pig? - Impressions and suggestions of a pathologist working in the field of toxicology

Abstract

Gross and histopathological investigations of more than 100 minipigs revealed: 1. Findings due to repeated blood sampling. For anatomical reasons the thyroid gland of pigs can be injured during blood sampling. Histopathological investigation of thyroid glands often revealed inflammatory and reparative fibrotic changes of this organ. Depending on the grade of damage, thyroid hormone levels may vary. To avoid misinterpretation of results, most careful blood sampling by experienced personnel is recommended. 2. Findings due to viral, bacterial and parasitic infections. These concerned mainly the lungs which often showed pneumonic alterations. In case of parasitic invasion, the skeletal muscles may reveal degenerative changes due to sarcosporidia (re-) infection. Therefore, optimal hygienic conditions, e.g. during blood sampling, and continuing health monitoring are recommended. 3. Findings due to preventive iron administration. Months after preventive iron-dextran administration at the breeding station, histopathological examination revealed siderin accumulation in a number of organs, namely in the cells of the mononuclear phagocytic system in liver and kidneys. As a unique finding an intraglomerular siderin deposition in the mesangial cells with subsequent glomerulosclerosis in certain glomeruli was observed.