@Stephanie-H I appreciate your concept. It's unique and interesting, and it's drawing my curiosity. I also really like your painterly style. Here are some notes to consider as you fine-tune (please disregard if these were already mentioned in other comments):
-Why a dog spirit and this one in particular? I've heard of Dalmatians being a known dog worker/helper at a fire station, but this dog isn't that breed so I'm wondering if it perished in the fire? (I only mention fire station because you mentioned that there was a fire.)
-It's unclear to me whether the dog is spewing clouds, or sucking in clouds. Maybe look up pictures of kids blowing bubbles--that gentle pursing of the lips. And the clouds could start as thin tendrils, expanding as it moves farther out.
-The dog looks so sweet and cute. But it looks like a real dog, rather than a dog spirit. What if you made the dog white with touches of blue like the clouds, and semi-transparent? Maybe there could be tiny delicate star shapes defining the lines of its body? OR, you can make the dog a much brighter, more intense color than the rest of the painting, just differentiating it from the other colors so it's definitely conjuring up supernatural vibes. I'm thinking of some Chagall paintings.
Hope some of these ideas are helpful. Looking forward to seeing your final image. Very exciting idea!