The dog has gotten into the hospital, partly to look for the person it wants to see and partly because its presence might help people feel better. People like dogs, after all, so its being there might do some good. It approaches the man, looking up towards him and panting. Its eyes are open wide. Pats! It wants pats!

There's an alien intelligence behind this dog, but even an alien intelligence likes pats and treats. This form makes it feel wanted, even helpful, to the people of this strange world. It can explain things later, once the situation has calmed down with the injuries and the last of the winter has ended.