The Prophet ﷺ did not take any zakat from horses or slaves.
حدثنا أبو اليمان حدثنا أبو بكر بن عبد الله عن راشد بن سعد عن عمر بن الخطاب رضي الله عنه
أن النبي ﷺ لم يأخذ من الخيل والرقيق صدقة
No references are available.
Its isnad is daif due to a break in the chain, since Rashid bin Saad did not meet Umar, and because Abu Bakr bin Abdullah bin Abu Maryam is daif due to his confusion and poor memory. See 82.