Question

He said to me, " horse had died at home " change narration

Answer 1

Here reported speech is in past parfect so accrding to the rule "if the reporting speech is in simple past tense and reported speech is in past perfect there dhoul be no change in the tense of reported speech"
So narration of given sentence woould be
He told me that horse had died at home.
One more thing there should be use of definite article the" before horse