Investigation of the pharmacokinetics of fentanyl patches at different locations on sheep

ARI Exploratory Research
T Buchholz, S Zeiter


The sheep is a frequently used animal model for orthopedic research at the ARI mostly involving invasive surgery on the hind limb. Therefore, the sheep need general anesthesia. These painful procedures can only be ethically justified with the application of an adequate analgesia protocol. A transdermal fentanyl patch is a great way of application to administer fentanyl over a longer period avoiding stressful injections for the animal.

The uptake of fentanyl through the skin depends on various factors (fat content of the skin, temperature, blood circulation). A comparison of different locations is needed to clarify the best and most feasible skin area to apply a transdermal fentanyl patch. With an identification of the characteristics of the uptake of fentanyl in sheep, the current analgesia protocol could be adapted in order to be more reliable.



In accordance with the refinement of the 3R principle, the aim of this study was to improve the analgesia protocols used at the ARI for sheep undergoing orthopedic surgery.

  • Publication

    Buchholz T, Hildebrand M, Heider A, Stenger V, Arens D, Spadavecchia C, Zeiter S. Transdermal Fentanyl Uptake at Two Different Patch Locations in Swiss White Alpine Sheep. Animals (Basel). 2020 Sep 17;10(9):E1675. doi: 10.3390/ani10091675. PMID: 32957484.

    Buchholz T. Transdermal Fentanyl uptake at two different patch locations in Swiss white alpine sheep. 2020 Universität Bern (C. Spadadvecchia, S. Zeiter) – DVM / Dr med vet (thesis)

  • Partners

    Spadavecchia C (Prof) VetSuisse University of Bern, Switzerland

    Rohrbach H (Dr med vet), VetSuisse University of Bern, Switzerland

    Heider A, Swiss Institute of Allergy and Asthma (SIAF), Davos, Switzerland