Is it permissible to burden an animal beyond its capacity?
Chapter on Maintenance of Slaves
Al-Mughni
Book of Maintenance (Nafaqāt)
Primary text
It is not permissible to burden an animal with what it cannot bear because it is analogous to a slave, and the Prophet (PBUH) forbade tasking a slave beyond their capacity. Furthermore, doing so involves tormenting an animal which inherently possesses sanctity, and causing it harm is not permissible.