Oh man that sounds so familiar @lynncoyl1 .. I hate reading this, but I recognize it exactly. Your dog felt it right.. I had a cat with my first born, and as soon as my daughter cried, and the cat heard here she came to me pushing her head against me and meowing saying, hurry up you hear her right? haha..
But at the same time while my oldest was such an easy baby (slept through the night after 10 days) and woke up herself, just looking around smiling in her crib without crying if I wasn't there right away.. my son was a bit different. And because my daughter indeed fell a sleep after a few minutes of crying when she was tired, my ex told me: let him cry it worked for her too.. babies need to cry themselves to sleep!
And my mother instinct told me this is different he is in pain. He cried as soon as I put him down, so I knew that he had a problem called reflux (not sure if the english word is the same..) I went to a check up told the doctor what I had noticed and he looked at me saying: "I don't need to tell you what's the problem, right? You already know that" So I said yeah I think it's reflux.. and he confirmed.. my son got medication and in a few days he was doing so much better..
I carried him around almost all day because then he would not have any pain, and he would only fall asleep lying down when he was drinking my milk. But I hate how my ex and his mother kept saying let him cry.. That was the moment I also decided that he would not be going there to have sleepovers, and stay with me.. because I would not feel comfortable at all when I knew they'd let him cry :(
Animals have a good sense of these things your dog is a good example :) Good that you decided to listen to your mommy instincts !