"Breaking" is an archaic term for training and animals, specifically "to train (an animal) to adjust to the service or convenience of humans" [Merriam-Webster]. But it is time to put this term to bed. Not only does it has connotation of damage and violence, it is out of tune with modern ethics that both human and animal should benefit from living or working together.
This obsolete term jumped out at me from a Chicago tribune report today. The article was covering the prosecution of Muddy paws Dog Rescue owner and operator Diane Eldrup. Eldrup clear succumbed to some kind of 'break down' herself in allowing at least eighteen dogs and three birds to starve to death in their cages.
Four dogs were recovered alive and are being carefully rehabilitated, including feeding them back to a healthy weight and house-training them. A wonderful activityy that is jarringly referred to as: "house-breaking". As if these dogs have not already been sufficiently 'broken'. Locked in a enclosure and not even given food and water in return.
Now they are being prepared a home, care and love. A contract which in turn requests that they be calm and defecate outside the house. An agreement based on co-operation, commitment, and a promise that--this time--should not be broken.