Blinded - This will not affect a standard mount much at all. Blinded does not inhibit movement so the mounted player can allocate a move action to the mount as usual. If the mount should attack, it would take the usual penalties.
Dominated - A mount can only take a standard/move/minor action if the mounted PC allocates that action to the mount. In general this means a dominated mount will perform no action. It's not perfectly clear but I believe that if a standard/move/minor action is allocated to the mount then the dominated condition will override it and allow the NPC who dominated the mount to specify the action. Note that the mount has it's own set of free actions which the dominator could use one of each turn. This doesn't seem useful in the general case but perhaps there are some mounts that could be taken advantage of this way.
Stunned - the mount can take no actions. Therefore no actions can be allocated to it, it will not move or attack.