SDCL § 56-1-22: Exoneration of guarantor--Alteration of original obligation of principal--Impairment of rights of creditors.

A guarantor is exonerated except so far as he may be indemnified by the principal if by any act of the creditor, without the consent of the guarantor, the original obligation of the principal is altered in any respect or the remedies or rights of the creditor against the principal in respect thereto in any way impaired or suspended.