If your neighbor has such a hankering for cats, let him or her assume the responsibility for their care. It seems to me that your garage could be put to better use. He takes his pacifier and eventually goes back to sleep. However, this is stressful for our family. I'm not sure.
Young children are almost always wary of unfamiliar situations and people.
This is a natural tendency that they usually outgrow. Parents and doctors are well aware that youngsters may have nightmares, which can be truly frightening. Physical causes are common factors in the situation you described. Colic, urinary infection, cold or wet diapers could be factors leading to your son's periodic fretfulness. I hope that you haven't misinterpreted your pediatrician's attitude as uncaring.