Provided is an absorbent article for a pet animal being capable of prevent urine leaking out of a tail opening. The absorbent article (10) includes a cutting line (30) forming the fail opening positioned on a dorsal region (12)side in an intermediate region(13) and an indicator(50) positioned on a body non-facing surface of an absorbent layer(25) and to show a color reaction by coming in contact with excreted urine. The absorbent layer (25) is positioned between the cutting line (30) and a ventral region (11) . The absorbent core (40) has a first end edge(40b)and a second end edge (40a) opposite to the first end edge(40b)in a longitudinal direction(Y), and the indicator (50) is positioned longitudinally outboard of at least the first end edge (40b) of the first end edge (40b) and the second end edge (40a).