A person may cause animals to suffer for the sake of livelihood, honor, or enjoyment. Thus, one may load animals with heavy packs and strike them to make them move; one may ride horses, guide them with a bit that hurts their mouths, and urge them forward with a whip or boot spurs. Just as a person may exert himself, sweat, and endure indignity in order to earn a living, so too his animal may share in the strain of that work. Since an animal’s stature and sensitivity are lower, it may be put to harder and more painful labor.
Indeed, just as people are sometimes prepared to endure very great suffering for the sake of their honor and religious commitments, so too, at times, it is permitted to cause animals to suffer for the sake of human honor and faith. For example, after a king died, his possessions would be burned in his honor so that others would not use them. This included hamstringing his horses – cutting their legs above the hooves so that they could no longer be used. Although this caused them very great suffering, the honor of the king, which is the honor of all Israel, takes precedence (Avoda Zara 11a; Tosafot, s.v. okrin).
Similarly, before Israel’s war against the kings of the north, it is stated (Yehoshua 11:6): “The Lord said to Yehoshua, ‘Do not fear them, for tomorrow at this time I will deliver all of them slain before Israel. You shall hamstring their horses and burn their chariots with fire.’” Yehoshua was commanded to hamstring the horses by cutting their legs above the hooves, so that they would limp on the stumps of their legs as a disgrace for having taken part in the war. Although the horses could have been taken as spoils or killed, he was commanded to leave them maimed, thereby teaching both the enemies and Israel a lesson: not to trust in horses (Radak; Abarbanel). Even though the hamstringing caused the horses great suffering, we learn from this that for a great moral purpose of this kind, it is permitted to cause them suffering.
We also find that the Sages penalized someone who went to do business on a market day devoted to idolatry: everything he bought there must be destroyed, and if he bought animals, their legs must be cut above the hooves so that he cannot benefit from them. Although this entails tza’ar ba’alei ḥayim, they decreed it in order to distance Israel from idolatry (Avoda Zara 13a; Tosafot, s.v. amar Abaye).
Similarly, R. Yehuda permitted selling a white rooster to a gentile, provided one first cut off its toe so that the gentile could not use it for idolatry. Thus, for financial gain, the Sages permitted causing it suffering by cutting off a toe (Mishna, Avoda Zara 13b).
The Sages also enacted that if someone consecrated an animal to the Temple when the Temple was in ruins, the animal should be placed in an enclosed area until it dies of starvation, so that people would not stumble by misusing consecrated property and using the animal. They did not suggest slaughtering it, which would reduce its suffering, lest people mistakenly eat its meat. Nor did they suggest killing it in some other manner, lest they appear to be inflicting a blemish on a consecrated animal (Avoda Zara 13b). Thus, to prevent people from erring, they accepted causing an animal to suffer by leaving it to die of starvation (Ramban to Avoda Zara 13b; R. Akiva Eger to Avoda Zara 13a notes that hamstringing is more painful).
Finally, an elderly person for whom it is beneath his dignity to unload a donkey is exempt from the mitzva, even though the donkey is suffering and lying under its burden. This too shows that human dignity takes precedence over animal suffering (Nimukei Yosef to Bava Metzia 32b).
