Funny, I was just thinking this today, and trying to remember if my mother in laws dog had acted differently around my wife since she got MECFS. Couldn't reallly recall.
A friend of mine posted a video the other day of a pug coming up to her when she was on a walk and then just sitting next to her and looking back in the direction she came from. Apparently she was deaf and lost. What I found interesting was my friends dog sniffed this Pugg all over and then came back to the ears for additional sniffs. Could smell that the pug was deaf.