It is permissible to lend animals and it is recommended to pay in full, giving something better than that which ts owed
حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارِ بْنِ عُثْمَانَ الْعَبْدِيُّ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ سَلَمَةَ بْنِ كُهَيْلٍ، عَنْ أَبِي سَلَمَةَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ كَانَ لِرَجُلٍ عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم حَقٌّ فَأَغْلَظَ لَهُ فَهَمَّ بِهِ أَصْحَابُ النَّبِيِّ صلى الله عليه وسلم فَقَالَ النَّبِيُّ صلى الله عليه وسلم " إِنَّ لِصَاحِبِ الْحَقِّ مَقَالاً - فَقَالَ لَهُمُ - اشْتَرُوا لَهُ سِنًّا فَأَعْطُوهُ إِيَّاهُ " . فَقَالُوا إِنَّا لاَ نَجِدُ إِلاَّ سِنًّا هُوَ خَيْرٌ مِنْ سِنِّهِ . قَالَ " فَاشْتَرُوهُ فَأَعْطُوهُ إِيَّاهُ فَإِنَّ مِنْ خَيْرِكُمْ - أَوْ خَيْرَكُمْ - أَحْسَنُكُمْ قَضَاءً " .
Abu Huraira (Allah be pleased with him) reported: Allah's Messenger (ﷺ) owed (something) to a person. He behaved in an uncivil manner with him. This vexed the Companions of the Prophet (ﷺ), whereupon Allah's Messenger (ﷺ) said: He who has a right is entitled to speak, and said to them (his Companions): Buy a camel for him and give that to him. They said: We do not find a camel (of that age) but one with better age than that. He said: Buy that and give that to him, for best of you or best amongst you are those who are best in paying off debt.