Get the air freshener or the dog out of there! The air freshener could be slowly ruining his nose. Some air fresheners work by numbing your nose so you don't smell unpleasant odors. If you're around them every once in a while, the damage is temporary, but being continuously exposed to them can permanently decrease your sense of smell. Your dog is no different, and if anything, dogs are more sensitive to chemicals than people are. Even if it's the kind of air freshener that simply masks unpleasant odors, it's still not good for his health.
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