Ziggy isn't human enough, most of the human pulse points, he doesn't have, also his heart is in his back and hard to feel the beat from the front of the chest.

However, he is breathing. Supported by the groaning and mumbling of Hiroki's name. Ziggy however is firmly entrenched in a nightmare about the first night after Shiro told him his beloved was dead. Allura might feel the incredible pain and loss emanating from him at this point