The Use of Minipigs in Dermal Toxicity Testing

Pigs have been extensively used for surgical and physiological research for years, due to their similarities to humans. For human medical research, wether the blood and lymph, or circulation, respiration, exctetion and urine, digestion, metabolism, nutrition, endocrine and nervous system, and especially the cutaneous system, it appears that the pig is the ideal experimetal animal. While rabits are commonly used for the assessment of primary dermal irritation, pigs or minipigs have been considered to be a good model for dermal permeability and toxicity studies. The skin of pigs fulfills the requirements of a model for human skin. Human and porcine skin are similar with regard to sparsity of the pelage, thickness and general morphology, epidermal cell turnover time and size, orientation and distribution of vessels in the skin. The particular thin haircoat and the lack of pigment of the minipig makes it ideal for dermal studies. The size of the animal also provides the additional practical advantage of abundant surface area for multiple‐site and long‐term testing. Non‐invasive skin examination methods of human dermatology, for example reflectometric skin color measurement or high‐resolution ultrasonography, can be used as monitoring tools in dermal toxicity studies with minipigs. Skin alterations can be easily quantified by these methods. Despite there are some limitations, all in all there is no animal species that mimics the human skin better than the pig.