The district attorney of the said judicial district shall receive no other fees nor other compensation for official services, and he shall represent the parishes of the said judicial district and all other public bodies therein in all litigation in which said parishes or said boards may be interested, and shall advise these bodies when so requested without extra compensation, provided, that in any litigations outside of his judicial district said district attorney shall be allowed actual expenses incident to such litigation.
La. R.S. § 16:145