May the curse of Allah be on the one who treats an animal harshly.

رسولُ اللَّهِ صلى اللَّه عليه وآله :  إنّ اللَّهَ يُحِبُّ الرِّفْقَ ويُعينُ علَيهِ، فإذا رَكِبْتُمُ الدَّوابَّ العُجْفَ فأنْزِلوها مَنازِلَها ، فإنْ كانتِ الأرضُ مُجْدِبَةً فانْجوا عَنها ، وإنْ كانتْ مُخْصِبةً فأنْزِلُوها مَنازِلَها . الكافي : 2 / 120 / 12 .

 The Prophet (SAWA) said, 'Verily Allah loves gentleness and He aids in implementing it, so when you ride a lean animal, dismount it at the right place for if the land is barren and arid then get away from it and if the land is lush and fertile then dismount the animal [and allow it to rest].' al-Kafi, v. 2, p. 120, no. 12

رسولُ اللَّهِ صلى اللَّه عليه وآله :  لا تَضْرِبوا الدَّوابَّ على‏ وُجوهِها؛ فإنَّها تُسَبِّحُ بحَمْدِ اللَّهِ . الكافي : 6 / 538 / 4 ، الخصال : 618 / 10 .

 The Prophet (SAWA) said, 'Do not hit animals on their faces for verily they praise and glorify Allah.' al-Kafi, v. 6, p. 538, no. 4 and al-Khisal, p. 618 no. 10

رسولُ اللَّهِ صلى اللَّه عليه وآله :  للدّابّةِ على‏ صاحِبِها سِتُّ خِصالٍ : يَعْلِفُها إذا نَزلَ ، ويَعْرِضُ علَيها الماءَ إذا مَرَّ بهِ ، ولا يَضْرِبُها إلّا على‏ حقٍّ ، ولا يُحَمّلُها ما لا تُطيقُ‏  ، ولا يُكلّفُها مِن السَّيرِ إلّا طاقَتَها ، ولا يَقِفُ علَيها فُواقاً . الجعفريّات : 85 ، مستدرك الوسائل : 8 / 258 / 9393 .

 The Prophet (SAWA) said, 'The animal has six rights over its owner: once the owner has dismounted the animal he should allow it to graze, he should give it access to water if they pass by it, he should not hit the animal except when it truly deserves it, he should not burden it with a load that it cannot bear, he should not overtask it with a journey that it cannot endure and he should not sit on it for lengthy periods of time.' al-Jafariyyat, p. 85 and Mustadrak al-Wasa'il, v. 8, p. 258, no. 9393

رسولُ اللَّهِ صلى اللَّه عليه وآله :  ارْكَبوا هذهِ الدَّوابَّ سالِمَةً واتَّدِعُوها سالِمَةً ، ولا تَتَّخِذوها كَراسِيَّ لأحاديثِكُم في الطُّرُقِ والأسْواقِ ، فَرُبَّ مَرْكوبَةٍ خَيرٌ مِن راكِبِها وأكْثَرُ ذِكْراً للَّهِ تباركَ وتعالى‏ مِنهُ . كنز العمّال : 24957 .

 The Prophet (SAWA) said, 'Mount the sound animals and look after them properly and do not treat them as chairs for your conversations in the streets and the markets, for many riding animals are better than their rider and are more remembering of Allah - Blessed and most High.' Kanz al-Ummal, no. 24957

رسولُ اللَّهِ صلى اللَّه عليه وآله :  ما مِن دابَّةٍ - طائرٍ ولا غَيرِهِ - يُقتَلُ بغَيرِ الحقِّ إلّا ستُخاصِمُهُ يَومَ القِيامَةِ . كنز العمّال : 39968 .

 The Prophet (SAWA) said, 'No animal, including a bird or any other kind, is killed unjustly except that it will raise a complaint against him [the killer] on the Day of Resurrection.' Kanz al-Ummal, no. 39968

رسولُ اللَّهِ صلى اللَّه عليه وآله :  غُفِرَ لامْرأةٍ مُومِسَةٍ مرَّتْ بكلبٍ على‏ رأسِ رَكِيٍّ يَلْهَثُ كادَ يَقْتُلُهُ العَطَشُ ، فنَزَعَتْ خُفَّها فأوْثَقَتْهُ بخِمارِها فنَزَعَتْ لَهُ مِن الماءِ ، فغُفِرَ لَها بذلكَ . كنز العمّال : 43116 .

 The Prophet (SAWA) said, 'A prostitute was forgiven when she passed a panting dog almost dying of thirst at the foot of a well, whereby she took off her shoe and tied it to her headscarf and lowered it into the well to extract water [for the dog], and for that action she was forgiven.' Kanz al-Ummal, no. 43116

رسولُ اللَّهِ صلى اللَّه عليه وآله :  ألَا تَتَّقي اللَّهَ في هذهِ البَهيمَةِ الّتي مَلّكَكَ اللَّهُ تعالى‏ إيّاها ؟! فإنّهُ شَكا إلَيّ أنّكَ تُجيعُهُ وتُدْئبُهُ . كنز العمّال : 24982 .

 The Prophet (SAWA) said, 'Are you not Godwary with respect to this animal that Allah has allowed you to possess?! Because verily it has complained to me that you keep it hungry and tire it out.' Kanz al-Ummal,  no. 24982

رسولُ اللَّهِ صلى اللَّه عليه وآله :  لَو غُفِرَ لَكُم ما تَأتونَ إلى‏ البَهائِم لَغُفِرَ لَكُم كَثيراً . كنز العمّال : 24973 .

 The Prophet (SAWA) said, 'If the oppression that you have committed towards animals is forgiven for you, then [realise that] you have been forgiven a lot [of your sins].' Kanz al-Ummal,  no. 24973

رسولُ اللَّهِ صلى اللَّه عليه وآله :  مَن قَتلَ عُصْفوراً عَبَثاً عَجَّ إلى‏ اللَّهِ يَومَ القِيامَةِ مِنهُ ، يقولُ : يا رَبِّ ، إنّ فُلاناً قَتلَني عَبَثاً ولَم يَقتُلْني لِمَنفَعَةٍ . كنز العمّال : 39971 .

 The Prophet (SAWA) said, 'Whoever kills a sparrow in vain, it will cry out to Allah against him on the Day of Resurrection saying, 'O my Lord, so and so killed me in vain and did not kill me for any useful purpose.' Kanz al-Ummal,  no. 39971

رسولُ اللَّهِ صلى اللَّه عليه وآله :  لَعنَ اللَّهُ مَن مَثَّلَ بالحَيوانِ . كنز العمّال : 24971 .

 The Prophet (SAWA) said, 'May the curse of Allah be on the one who treats an animal harshly.' Kanz al-Ummal,  no. 24971