@beaconlight94 Second looking up littermate syndrome. Two adolescent puppies shouldn't be raised with a large amount of access to each other and should be spending the majority of their time separately, out of view of each other.
@taz77777 How old are they? Because I see ppl who are like "my puppies who were raised together and are 1.5 y/o have been perfect until the last week when they suddenly started showing aggression towards each other". Like, why risk it?