Received: 24 January 2020
Accepted: 4 May 2020
First Online: 24 May 2020
Ethics approval and consent to participate
: The horses were cared for according to accepted veterinary practices. The study was approved by the State Office for Consumer Protection and Food Safety (LAVES) in accordance with the German Animal Welfare Law (case number: 33.8–42502–04-17/2646).
: Not applicable.
: The authors declare that they have no competing interests.