On the day of Khaibar, Messenger of Allah ﷺ forbade the eating of donkey meat and allowed the eating of horse meat.  

نَهَى رَسُولُ اللَّهِ ﷺ يَوْمَ خَيْبَرَ عَنْ لُحُومِ الْحُمُرِ وَرَخَّصَ فِي الْخَيْلِ  

We slaughtered a horse (by Nahr) during the lifetime of the Prophet ﷺ and ate it.  

عَنْ أَسْمَاءَ بِنْتِ أَبِي بَكْرٍ ؓ قَالَتْ نَحَرْنَا عَلَى عَهْدِ النَّبِيِّ ﷺ فَرَسًا فَأَكَلْنَاهُ