Pharmacokinetics and adverse reactions to fentanyl transdermal patches in healthy and hospitalized calves

Fentanyl is a mu opioid receptor agonist that has been used for analgesia in multiple species. One of the more common routes of administration of fentanyl is the transdermal route. There have been multiple reports ofthe use of Fentanyl Transdermal Patches (FTP) in large animal practice as a longer-term method of analgesia. The use of the patches has been described for analgesia in horses, sheep, goats, pigs, and llamas, but there is no data available for the use of this extended-release formulation in cattle.