Working animals perform practical jobs for humans across farms, security, medicine, and military settings. Classic examples include herding and guard dogs that protect livestock, draft and rescue breeds that haul loads or find people, and detection dogs that locate bombs, drugs, or medical warning signs such as seizures.
Other species do specialized work too: military dolphins and sea lions help find underwater mines, trained rats detect land mines in parts of Africa and Asia, and miniature horses can serve as guide animals. Capuchin monkeys have also been trained to help people with mobility impairments with everyday tasks.
Source: Britannica — Working Like a Dog: 7 Animals with Jobs