Do you understand your pet what ther're saying?

Do you understand your pet what ther're saying? I have lived with my dog for 9 years. Although I live together long tme, sometime I don't understand what he says.
When we were Korea New Year, my family went to the grandfather's house. So I put my dog in an animal house for 3 days. After that I brought my dog from an animal house, I felt strange. Because whenever he see me, he usually licks me. But at that time, he didn't lick me, also his eyes loocked a little bit different.
The monent I think someone could have hit my dog. My dog is as meek as a lamb and before I never hit him, so if someone hit him, he might have gotten a shock.
Also I guess that someone might have given him which he doesen't like food, because he really likes eatting meats. If I give him just dry dog foods, he never eat it. I have to mix dry dog foods and a can dog food.
Another possibility is that he might have been disappointed in love. There is lots of dogs in an animal house. He probably fell in love. But he came back home, he couldn't meet her who he fell in love. So his feeling is not good.
I don't know correctly, but I just know his feeling is uncomfortable. We wouldn't put my dog in an animal house. So whenever my family leave the house, we never put my dog in an animal house.